Common Core Math Grade 4 Fraction Addition Subtraction

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Comm Co mmon on Co Core re Mathematics Teacher Resource Book 4

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Teacher S Resource Book • Table of Contents • Pacing Guides • Correlation Charts • Sample Lessons For a complete Teacher Resource Book call 800-225-0248

Table of Contents Ready ® Common Core Program Core Program Overview

A6

Supporting the Implementation of the Common Core

A7

Answering the Demands of the Common Core with Ready

A8

The Standards for for Mathematical Mathematical Practice

A9

Depth of Knowledge Level 3 Items in Ready Common Core

A10

Cognitive Cognitiv e Rigor Matrix

A11

Using Ready Common Core

A12

Teaching T eaching with Ready Common Core Instruction

A14

Content Emphasis in the Common Core Standards

A16

Connecting with the Ready® Teacher Toolbox

A18

Using i-Ready® Diagnostic with with Ready Common Core

A20

Features of Ready Common Core Instruction

A22

Supporting Research

A38

Correlation Charts Common Core State Standards Coverage by Ready Instruction

A42

Interim Assessment Correlat Correlations ions

A46

Lesson Plans (with Answers) CCSS Emphasis Unit 1: Number and Operations in Base Ten, Part 1

1

Understand Place Value

3

M

11

M

19

M

29

M

Lesson 1

CCSS Focus - 4.NBT.A.1, 2

Lesson 2

Compare Whole Numbers

CCSS Focus - 4.NBT.A.2

Lesson 3

Embedded SMPs - 2, 4, 6–8

Add and Subtract Whole Numbers

CCSS Focus - 4.NBT.B.4

Lesson 4

Embedded SMPs - 2, 4, 6, 7


Round Whole Numbers

CCSS Focus - 4.NBT.A.3


Unit 1 Interim Assessment

Unit 2: Operations and Algebraic Thinking Lesson 5

Understand Multiplication

CCSS Focus - 4.OA.A.1

Lesson 6

40 42

M

50

M

Embedded SMPs - 2–4

Multiplication and Division in Word Problems


37

Embedded SMPs - 2–5, 7

M = Lessons that have a major emphasis in the Common Core Standards Standards S/A = Lessons that have supporting/additional emphasis in the Common Core Standards

CCSS Emphasis Unit 2: Operations and Algebraic Thinking (continued) Lesson 7

Multiples and Factors

CCSS Focus - 4.OA.B.4

Lesson 8

Lesson 9

Lesson 10

S/A S/ A

82

M

90

M


Solve Multi-Step Problems


72


Model Multi-Step Problems


S/A S/ A

Embedded SMPs - 2, 5, 7

Number and Shape Patterns

CCSS Focus - 4.OA.C.5

60



99

Unit 3: Number and Operations in Base Ten, Part 2

102 10 2

Multiply Whole Numbers

105 10 5

M

115

M

Lesson 11


Lesson 12


Divide Divid e Whole Number Numberss




Unit 4: Number and Operations—Fractions Lesson 13

Understand Equival Equivalent ent Fracti Fractions ons

CCSS Focus - 4.NF.A.1

Lesson 14

Lesson 15

Understand Fraction Addition and Subtraction

Add and Subtract Mixed Numbers

Lesson 20

M

158

M

168

M

178

M

186

M

194

M


Fractions as Te Tenths nths and Hundredths

CCSS Focus - 4.NF.C.5

150


Multiply Fractions

CCSS Focus - 4.NF.B.4c

M


Understand Fracti Fraction on Multipli Multiplication cation

CCSS Focus - 4.NF.B.4a, 4b

Lesson 19

140


CCSS Focus - 4.NF.B.3b, 3c, 3d

Lesson 18

M


Add and Subtract Fractions

CCSS Focus - 4.NF.B.3a, 3d

Lesson 17

132

Embedded SMPs - 1, 2, 4, 5, 7

CCSS Focus - 4.NF.B.3a, 3b

Lesson 16

130

Embedded SMPs - 2–4, 7, 8

Compare Fractions

CCSS Focus - 4.NF.A.2

125


M = Lessons that have a major emphasis in the Common Core Standards Standards S/A = Lessons that have supporting/additional emphasis in the Common Core Standards

CCSS Emphasis Unit 4: Number and Operations—Fractions (continued) Lesson 21

Relate Decimals and Fractions


Lesson 22

M

212

M

Embedded SMPs - 2, 4–7

Compare Decimals


202



223

Unit 5: Measurement and Data

226

Lesson 23

Convert Measurements

CCSS Focus - 4.MD.A .1

Lesson 24

Lesson 25

Lesson 26

Lesson 27

Lesson 28

Understand Angles

Lesson 30

Unit 6: Geometry

Lesson 32

Lesson 33

S/A

291

S/A

301

S/A

311

316

S/A

328

S/A

340

S/A

Embedded SMPs - 3, 5, 8

Symmetry

CCSS Focus - 4.G.A.3

283


Classify Two-Dimensional Figures


S/A

314

Points, Lines, Rays, and Angles


271



Lesson 31

S/A


Add and Subtract With Angles

CCSS Focus - 4.MD.C.7

261

Embedded SMPs - 6, 7

Measure and Draw Angles

CCSS Focus - 4.MD.C.6

S/A


CCSS Focus - 4.MD.C.5a, 5b

Lesson 29

249


Line Plots

CCSS Focus - 4.MD.B.4

S/A


Perimeter and Area

CCSS Focus - 4.MD.A.3

239


Length, Liquid Volume, and Mass


S/A


Time and Money


229



M = Lessons that have a major emphasis in the Common Core Standards S/A = Lessons that have supporting/additional emphasis in the Common Core Standards

350

Answering the Demands of the Common Core with Ready® THE DEMANDS OF THE COMMON CORE Focus:

The Common Core Standards for Mathematics focus on fewer topics each year, allowing more time to truly learn a topic. Lessons need to go into more depth to help students to build better foundations and understanding.

Coherent Connections (Building on Prior Knowledge):

Instruction needs to provide logical ways for students to make connections between topics within a grade as well as across multiple grades. Instruction must build on prior knowledge and be organized to take advantage of the natural connections among standards within each cluster as well as connections across clusters or domains. This coherence is required for students to make sense of mathematics. Rigor and Higher-Order Thinking:

To meet the Standards, equal attention must be given to conceptual understanding, procedural skill and fluency, and applications in each grade. Students need to use strategic thinking in order to answer questions of varying difficulty requiring different cognitive strategies and higher-order thinking skills. Conceptual Understanding:

In the past, a major emphasis in mathematics was on procedural knowledge with less attention paid to understanding math concepts. The Common Core explicitly identifies standards that focus on conceptual understanding. Conceptual understanding allows students to see math as more than just a set of rules and isolated procedures and develop a deeper knowledge of mathematics. Mathematical Practices:

The Standards for Mathematical Practice (SMP) must support content standards and be integrated into instruction. The content standards must be taught through intentional, appropriate use of the practice standards. Mathematical Reasoning:

Mathematical reasoning must play a major role in student learning. Students must be able to analyze problems, determine effective strategies to use to solve them, and evaluate the reasonableness of their solutions. They must be able to explain their thinking, critique the reasoning of others, and generalize their results.

HOW READY® DELIVERS Ready lessons reflect the same focus as the Common Core standards. In fact, the majority of the lessons in each grade directly address the major focus of the year. Furthermore, each lesson was newly-written specifically to address the Common Core Standards. There is at least one lesson for each standard and only lessons that address the Common Core Standards are included. Ready units are organized by domains following the cluster headings of the Common Core. Each lesson starts by referencing prior knowledge and making connections to what students already know, particularly reinforcing algebraic thinking and problem-solving. These connections are highlighted for teachers in the Learning Progressions of the Teachers Resource Book so teachers can see at a glance how the lesson connects to previous and future learning. Ready lessons balance conceptual understanding, skill and procedural fluency, and applications. Students are asked higher-order thinking questions throughout the lessons. They are asked to understand, interpret, or explain concepts, applications, skills and strategies. Practice questions match the diversity and rigor of the Common Core standards. Ready includes conceptual understanding in every lesson through questions that ask students to explain models, strategies, and their mathematical thinking. In addition, a “Focus on Math Concepts” lesson is included for every Common Core standard that focuses on conceptual development—those standards that begin with the word “understand.”

The Standards for Mathematical Practice are fully integrated in an age-appropriate way throughout each lesson. The Teachers Resource Book includes SMP Tips that provide more in-depth information for select practice standards addressed in the lesson. See pages A9 and A26 for more details. Ready lessons build on problem-solving as a main component of instruction. Students work through a problem, discuss it, draw conclusions, make generalizations, and determine the reasonableness of their solutions. Guided Practice problems ask students to critique arguments presented by fictional characters and justify their own solutions.

A8 ©Curriculum Associates, LLC Copying is not permitted.

The Standards for Mathematical Practice Mastery of the Standards for Mathematical Practice (SMP) is vital for educating students who can recognize and be proficient in the mathematics they will encounter in college and careers. As the chart below shows, the SMPs are built into the foundation of Ready ® Instruction . 1. Make sense of problems and persevere in solving them:

Try more than one approach, think strategically, and succeed in solving problems that seem very difficult. Each Ready lesson leads students through new problems by using what they already know, demonstrates multiple approaches and access points, and gives encouraging tips and opportunities for cooperative dialogue. 2. Reason abstractly and quantitatively:

Represent a word problem with an equation, or other symbols, solve the math, and then interpret the solution to answer the question posed. Ready lessons lead students to see mathematical relationships connecting equations, visual representations, and problem situations. Each lesson challenges students to analyze the connection between an abstract representation and pictorial or real-world situations.

3. Construct viable arguments and critique the reasoning of others:

Discuss, communicate reasoning, create explanations, and critique the reasoning of others. In Ready , the teacher-led Mathematical Discourse feature guides students through collaborative reasoning and the exchange of ideas and mathematical arguments. Ready lessons also provide erroranalysis exercises that ask students to examine a fictional student’s wrong answer, as well as multiple opportunities to explain and communicate reasoning.

4. Model with mathematics:

Use math to solve actual problems. Students create a mathematical model using pictures, diagrams, tables, or equations to solve problems in each Ready lesson. In the Teacher Resource Book, the Real-World Connection feature adds another dimension to understanding application of a skill. 5. Use appropriate tools strategically:

Make choices about which tools, if any, to use to solve a problem. Ready lessons model the use of a variety of tools, including diagrams, tables, or number lines; Guided Practice problems may be solved with a variety of strategies.

6. Attend to precision:

Explain and argue, draw, label, and compute carefully and accurately. Ready lessons guide students to focus on precision in both procedures and communication, including special error-analysis tasks and group discussion questions that motivate students to employ precise, convincing arguments. 7. Look for and make use of structure:

Build mathematical understanding by recognizing structures such as place value, decomposition of numbers, and the structure of fractions. Each Ready Focus on Math Concepts lesson builds understanding of new concepts by explicitly reviewing prior knowledge of mathematical structure. 8. Look for and express regularity in repeated reasoning:

Recognize regularity in repeated reasoning and make generalizations or conjectures about other situations. Each Ready lesson leads students to focus attention on patterns that reflect regularity. Where appropriate, students draw a conclusion or make a generalization and explain their reasoning by referencing the observed pattern.


Depth of Knowledge Level 3 Items in Ready® Common Core The following table shows the Ready ® lessons and sections with higher-complexity items, as measured by Webb’s Depth of Knowledge index.

Depth of Knowledge Level 3 Items in Ready Common Core Lesson

Section

Item

Lesson

Section

Item

1

Guided Practice

14

18

Guided Practice

13

1

Guided Practice

16

18

Guided Practice

14

1

Performance Task

17

18

Performance Task

16

2

Guided Practice

10

19

Guided Practice

10

3

Guided Practice

16

20

Guided Practice

11

4

Guided Practice

11

21

Guided Practice

17

4

Common Core Practice

6

21


5

Unit 1

Interim Assessment

7

22

Guided Practice

17

Unit 1

Interim Assessment

PT

Unit 4

Interim Assessment

PT

5

Guided Practice

11

23

Guided Practice

17

5

Guided Practice

12

24

Guided Practice

17

5

Guided Practice

13

24


5

6

Guided Practice

20

25

Guided Practice

25

7

Guided Practice

25

26

Guided Practice

19

8

Guided Practice

17

27

Guided Practice

20

8


2

28

Guided Practice

15

9

Guided Practice

10

28

Guided Practice

16

10

Guided Practice

11

28

Guided Practice

17

Interim Assessment

PT

28

Performance Task

18

11

Guided Practice

18

29

Guided Practice

19

12

Guided Practice

16

29


5

Unit 3

Interim Assessment

5

30

Guided Practice

17

Unit 3

Interim Assessment

PT

Unit 5

Interim Assessment

PT

13

Guided Practice

14

31

Guided Practice

23

13

Guided Practice

15

31


5

13

Performance Task

16

32

Guided Practice

21

14

Guided Practice

19

32


4

15

Guided Practice

14

33

Guided Practice

16

16

Guided Practice

18

33


4

17

Guided Practice

18

Unit 6

Interim Assessment

PT

Unit 2

A10 ©Curriculum Associates, LLC

Copying is not permitted.

Cognitive Rigor Matrix The following table combines the hierarchies of learning from both Webb and Bloom. For each level of hierarchy, descriptions of student behaviors that would fulfill expectations at each of the four DOK levels are given. For example, when students compare solution methods, there isn’t a lower-rigor (DOK 1 or 2) way of truly assessing this skill. Depth of Thinking (Webb) 1 Type of Thinking (Revised Bloom) Remember

Understand

Apply

DOK Level 1 Recall & Reproduction

DOK Level 2 Basic Skills & Concepts

DOK Level 4 Extended Thinking

• Recall conversations, terms, facts • Evaluate an expression • Locate points on a grid or number on number line • Solve a one-step problem • Represent math relationships in words, pictures, or symbols

• Specify, explain • Use concepts to solve • Relate mathematical concepts to other relationships non-routine problems content areas, other • Make basic inferences or • Use supporting evidence to justify conjectures, domains logical predictions from data/observations generalize, or connect • Develop generalizations ideas of the results obtained • Use models/diagrams to and the strategies used explain concepts • Explain reasoning when more than one response and apply them to new • Make and explain is possible problem situations estimates • Explain phenomena in terms of concepts

• Follow simple procedures • Calculate, measure, apply a rule (e.g.,rounding) • Apply algorithm or formula • Solve linear equations • Make conversions

• Select a procedure and perform it • Solve routine problem applying multiple concepts or decision points • Retrieve information to solve a problem • Translate between representations

• Design investigation for • Initiate, design, and conduct a project that a specific purpose or specifies a problem, research question identifies solution paths, • Use reasoning, planning, and supporting evidence solves the problem, and reports results • Translate between problem and symbolic notation when not a direct translation

• Retrieve information from a table or graph to answer a question • Identify a pattern/trend

• Categorize data, gures • Organize, order data • Select appropriate graph and organize and display data • Interpret data from a simple graph • Extend a pattern

• Compare information within or across data sets or texts • Analyze and draw conclusions from data, citing evidence • Generalize a pattern • Interpret data from complex graph

• Analyze multiple sources of evidence or data sets

• Cite evidence and develop a logical argument • Compare/contrast solution methods • Verify reasonableness

• Apply understanding in a novel way, provide argument or justification for the new application

• Develop an alternative solution • Synthesize information within one data set

• Synthesize information across multiple sources or data sets • Design a model to inform and solve a practical or abstract situation

Analyze

Evaluate

Create

DOK Level 3 Strategic Thinking & Reasoning

• Brainstorm ideas, concepts, problems, or perspectives related to a topic or concept

SBAC, 2012; adapted from Hess et al., 2009 ©Curriculum Associates, LLC


• Generate conjectures or hypotheses based on observations or prior knowledge and experience

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Using Ready ® Common Core Use Ready ® as Your Primary Instructional Program Because every Common Core Standard is addressed with clear, thoughtful instruction and practice, you can use Ready ® Common Core as your primary instructional program for a year-long mathematics course. The lesson sequence is based on the learning progressions of the Common Core to help students build upon earlier learning, develop conceptual understanding, use mathematical practices, and make connections among concepts.

Instruct Teach one Ready ® Common Core Instruction lesson per week, using the Pacing Guides on pages A14 and A15 for planning. Use the web-based, electronic resources found in the Teacher Toolbox to review prerequisite skills and access on-level lessons as well as lessons from previous grades. See pages A18 and A19 for more information.

Assess and Monitor Progress Assess student understanding using the Common Core Practice and Interim Assessments in Ready Common Core Instruction . See pages A29 and A46 for more information. Monitor progress using the benchmark tests in Ready ® Practice to assess cumulative understanding, identify student weaknesses for reteaching, and prepare for Common Core assessments.

Differentiate Instruction Identify struggling students and differentiate instruction using the Assessment and Remediation pages at the end of each lesson in the Teacher Resource Book . See page A23 for a sample. Access activities and prerequisite lessons (including lessons from other grades) in the Teacher Toolbox to reteach and support students who are still struggling. See pages A18 and A19 for more details.

Use Ready® with the i-Ready®Diagnostic You can add the i-Ready Diagnosti c as part of your Ready solution. • Administer the i-Ready Diagnostic as a cross-grade-level assessment to pinpoint what students know and what they need to learn. • Use the detailed individual and classroom diagnostic reports to address individual and classroom instructional needs using the lessons in Ready Common Core Instruction and the Teacher Toolbox . See pages A20 and A21 for more information. A12

©Curriculum Associates, LLC Copying is not permitted.

Using Ready® to Supplement Your Current Math Program If your instructional program was not written specifically to address the Common Core Standards, then your textbook likely does not include the concepts, skills, and strategies your students need to be successful. By supplementing with Ready ® Common Core Instruction, you’ll be able to address these concerns:

• Filling gaps in mathematics content that has shifted from another grade • Incorporating Common Core models and strategies into instruction • Integrating the habits of mind that are in the Standards for Mathematical Practice • Asking questions requiring students to engage in higher-level thinking, such as questions that ask students to explain effective strategies used to solve problems, critique the reasoning of others, and generalize their results • Including lessons and questions that develop conceptual understanding • Providing rigorous questions modeled on the latest Common Core assessment frameworks

Step-by-Step Implementation Plan How do I know what to teach?

• Identify the Ready lessons you need to include in your instructional plan. STEP 1 IDENTIFY CONTENT NEEDS

− First identify the Ready lessons that address standards that are a major emphasis in the Common Core. See page A16 or the Table of Contents to easily identify these Ready lessons. − Next, identify the Common Core standards in the table on page A17 that are not addressed in your current math program. • Identify the place in your scope and sequence to insert the Ready lessons. “Focus on Math Concepts” lessons should come before the lesson in your current book. How do I make time to teach the Ready lessons?

STEP 2 INTEGRATE READY

• Remove lessons or units from your current instructional plan that are no longer covered in the Common Core standards at that grade level. • Replace lessons or units that do not teach topics using the models, strategies, and r igor of the Common Core with the appropriate Ready lessons. How can I address gaps in student knowledge?

STEP 3 MEASURE STUDENT PROGRESS

• Use the Interim Assessments in Ready to make sure your students are successfully able to meet the rigorous demands of the Common Core. • Use the benchmark tests in Ready ® Practice to identify student weaknesses and gaps in students’ knowledge. • Use the Ready ® Teacher Toolbox to access activities, on-level lessons, and lessons from other grades to address gaps in students’ background and learning. See pages A18 and A19 for more on the Teacher Toolbox .



Teaching with Ready® Common Core Instruction Ready Instruction Year-Long Pacing Guide

Week

1 2 3 4 5

6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23

24 25 26 27 28 29 30 31 32

33 34 35 36

A14

Ready® Common Core Instruction Lesson

Days

Minutes/day

Practice Test 1 or i-Ready Baseline Diagnostic L1: Understand Place Value L2: Compare Whole Numbers L3: Add and Subtract Whole Numbers L4: Round Whole Numbers Unit 1 Interim Assessment L5: Understand Multiplication L6: Multiplication and Division in Word Problems L7: Multiples and Factors L8: Number and Shape Patterns L9: Model Multi-Step Problems L10: Solve Multi-Step Problems Unit 2 Interim Assessment L11: Multiply Whole Numbers L12: Divide Whole Numbers Unit 3 Interim Assessment L13: Understand Equivalent Fractions L14: Compare Fractions L15: Understand Fraction Addition and Subtraction L16: Add and Subtract Fractions L17: Add and Subtract Mixed Numbers L18: Understand Fraction Multiplication L19: Multiply Fractions L20: Fractions as Tenths and Hundredths L21: Relate Decimals and Fractions L22: Compare Decimals Unit 4 Interim Assessment Practice Test 2 or i-Ready Interim Diagnostic L23: Convert Measurements L24: Time and Money L25: Length, Liquid Volume, and Mass L26: Perimeter and Area L27: Line Plots L28: Understand Angles L29: Measure and Draw Angles L30: Add and Subtract With Angles Unit 5 Interim Assessment L31: Points, Lines, Rays, and Angles L32: Classify Two-Dimensional Figures L33: Symmetry Unit 6 Interim Assessment

3 5 5 5 5 1 5 5 5 5 5 5 1 5 5 1 5 5 5 5 5 5 5 5 5 5 1 3 5 5 5 5 5 5 5 5 1 5 5 5 1

60 30–45 30–45 30–45 30–45 30–45 30–45 30–45 30–45 30–45 30–45 30–45 30–45 30–45 30–45 30–45 30–45 30–45 30–45 30–45 30–45 30–45 30–45 30–45 30–45 30–45 30–45 60 30–45 30–45 30–45 30–45 30–45 30–45 30–45 30–45 30–45 30–45 30–45 30–45 30–45

Practice Test 3 or i-Ready Year-End Diagnostic

3

60


Ready® Instruction Weekly Pacing (One Lesson a Week) Use Ready Common Core Instruction as the foundation of a year-long mathematics program. The Year-Long Sample Week (below) shows a recommended schedule for teaching one lesson per week. Each day is divided into periods of direct instruction, independent work, and assessment. Use the Year-Long Pacing Guide on page A14 for a specific week-to-week schedule.

Whole Class

Day 1

Day 2

Day 3

Day 4

Day 5

Introduction

Modeled/Guided Instruction

Modeled/Guided Instruction

Guided Practice


Introduction, including Vocabulary (30 minutes)

Discuss graphic and verbal representations of a problem.

Mathematical Visual Support Discourse (10 min) (15 minutes)

Small Group/ Independent

Assessment

Discuss graphic and verbal representations of a problem.

Discuss a sample problem. (10 minutes)

Concept Extension (15 minutes)

Hands-On Activity Work the math Work the math Work three (where applicable) with a symbolic with a symbolic problems representation and representation and independently, then practice with Try It practice with Try It Pair/Share. problems. problems. (20 minutes) (20 minutes) (20 minutes)

Solve problems in test format or complete a Performance Task. (30 minutes)

Discuss answer to the Reflect question. (5 minutes)

Review solutions and explanations. (15 minutes)

Discuss solutions to Discuss solutions to Check solutions the Try It the Try It and facilitate Pair/ problems. problems. Share. (10 minutes) (10 minutes) (15 minutes)

Assessment and Remediation (time will vary)

Ready Instruction Weekly Pacing (Two Lessons a Week) Target Ready Common Core Instruction lessons based on Ready Common Core Practice results to focus learning in a compressed time period. The chart below models teaching two lessons per week. The two lessons are identified as Lesson A and Lesson B in the chart below. Day 1

In Class

Day 2

Day 3

Lesson A

Lesson A

Introduction (15 minutes)

Guided Instruction Introduction (15 minutes) (15 minutes)

Modeled Instruction (30 minutes)

Guided Practice (30 minutes)

Homework (optional)

Lesson B

Modeled Instruction (30 minutes)

Day 4

Day 5

Lesson B

Lesson A Review concepts Guided Instruction and skills (15 minutes) (20 minutes) Guided Practice Lesson B (30 minutes) Review concepts and skills (20 minutes)

Lesson A

Lesson B





Correlation Charts Common Core State Standards Coverage by Ready® Instruction The table below correlates each Common Core State Standard to the Ready ® Common Core Instruction lesson(s) that offer(s) comprehensive instruction on that standard. Use this table to determine which lessons your students should complete based on their mastery of each standard.

Content Emphasis

Ready ® Common Core Instruction Lesson(s)

Interpret a multiplication equation as a comparison, e.g., interpret 35 = 5 3 7 as a statement that 35 is 5 times as many as 7 and 7 times as many as 5. Represent verbal statements of multiplicative comparisons as multiplication equations.

Major

5

Multiply or divide to solve word problems involving multiplicative comparison, e.g., by using drawings and equations with a symbol for the unknown number to represent the problem, distinguishing multiplicative comparison from additive comparison.

Major

6

Solve multistep word problems posed with whole numbers and having whole-number answers using the four operations, including problems in which remainders must be interpreted. Represent these problems using equations with a letter standing for the unknown quantity. Assess the reasonableness of answers using mental computation and estimation strategies including rounding.

Major

9, 10

Supporting/ Additional

7


8

4.NBT.A.1 Recognize that in a multi-digit whole number, a digit in one place represents ten times what it represents in the place to its right. For example, recognize that 700 4 70 5 10 by applying concepts of place value and division.

Major

1

4.NBT.A.2 Read and write multi-digit whole numbers using base-ten numerals, number names, and expanded form. Compare two multi-digit numbers based on meanings of the digits in each place, using ., 5, and , symbols to record the results of comparisons.

Major

1, 2

4.NBT.A.3 Use place value understanding to round multi-digit whole numbers to any place.

Major

4

Common Core State Standards for Grade 4 — Mathematics Standards Operations and Algebraic Thinking Use the four operations with whole numbers to solve problems. 4.OA.A.1

4.OA.A.2

4.OA.A.3

Gain familiarity with factors and multiples. 4.OA.B.4

Find all factor pairs for a whole number in the range 1–100. Recognize that a whole number is a multiple of each of its factors. Determine whether a given whole number in the range 1–100 is a multiple of a given one-digit number. Determine whether a given whole number in the range 1–100 is prime or composite.

Generate and analyze patterns. 4.OA.C.5

Generate a number or shape pattern that follows a given rule. Identify apparent features of the pattern that were not explicit in the rule itself. For example, given the rule “Add 3” and the starting number 1, generate terms in the resulting sequence and observe that the terms appear to alternate between odd and even numbers. Explain informally why the numbers will continue to alternate in this way.

Number and Operations in Base Ten Generalize place value understanding for multi-digit whole numbers.

Use place value understanding and properties of operations to perform multi-digit arithmetic. 4.NBT.B.4 Fluently add and subtract multi-digit whole numbers using the standard algorithm.

Major

3

4.NBT.B.5 Multiply a whole number of up to four digits by a one-digit whole number, and multiply two two-digit numbers, using strategies based on place value and the properties of operations. Illustrate and explain the calculation by using equations, rectangular arrays, and/or area models.

Major

11

The Standards for Mathematical Practice are integrated throughout the instructional lessons.

Common Core State Standards © 2010. National Governors Association Center for Best Practices and Council of Chief State School Officers. All rights reserved.

A42


Common Core State Standards for Grade 4 — Mathematics Standards

Content Emphasis


Number and Operations in Base Ten (continued) Use place value understanding and properties of operations to perform multi-digit arithmetic. (continued) 4.NBT.B.6 Find whole-number quotients and remainders with up to four-digit dividends and one-digit divisors, using strategies based on place value, the properties of operations, and/or the relationship between multiplication and division. Illustrate and explain the calculation by using equations, rectangular arrays, and/or area models.

Major

12

Explain why a fraction a is equivalent to a fraction (n 3 a) by using visual fraction (n 3 b) b ······ · models, with attention to how the number and size of the parts differ even though the two fractions themselves are the same size. Use this principle to recognize and generate equivalent fractions.

Major

13

Compare two fractions with different numerators and different denominators, e.g., by creating common denominators or numerators or by comparing to a benchmark fraction such as 1. Recognize that comparisons are valid only when the two fractions 2 ·· refer to the same whole. Record the results of comparisons with symbols ., 5, or ,, and justify the conclusions, e.g., by using a visual fraction model.

Major

14

Major

15, 16, 17

Major

15, 16

Major

15, 17

Add and subtract mixed numbers with like denominators, e.g., by replacing each mixed number with an equivalent fraction, and/or by using properties of operations and the relationship between addition and subtraction.

Major

17

Solve word problems involving addition and subtraction of fractions referring to the same whole and having like denominators, e.g., by using visual fraction models and equations to represent the problem.

Major

16, 17

4.NF.B.4

Apply and extend previous understandings of multiplication to multiply a fraction by a whole number.

Major

18, 19

4.NF.B.4a

Understand a fraction a as a multiple of 1 . For example, use a visual · b b ·· fraction model to represent 5 as the product 5 3 1 , recording the conclusion 4 4 ·· ·· by the equation 5 5 5 3 1 .

Major

18

Understand a multiple of a as a multiple of 1, and use this understanding · b b ·· to multiply a fraction by a whole number. For example, use a visual fraction model to express 3 3 2 as 6 3 1 , recognizing this product as 6 . 5 5 5 ·· ·· ·· (In general, n 3 1 a 2 5 (n 3 a) .)

Major

18

Solve word problems involving multiplication of a fraction by a whole number, e.g., by using visual fraction models and equations to represent the problem. For example, if each person at a party will eat 3 of a pound of 8 ·· roast beef, and there will be 5 people at the party, how many pounds of roast beef will be needed? Between what two whole numbers does your answer lie?

Major

19

Number and Operations—Fractions Extend understanding of fraction equivalence and ordering. 4.NF.A.1

4.NF.A.2

Build fractions from unit fractions. 4.NF.B.3

Understand a fraction a with a . 1 as a sum of fractions 1.

4.NF.B.3a

Understand addition and subtraction of fractions as joining and separating parts referring to the same whole.

4.NF.B.3b

Decompose a fraction into a sum of fractions with the same denominator

· b

b ··

in more than one way, recording each decomposition by an equation. Justify decompositions, e.g., by using a visual fraction model. Examples: 3

8 ··

4.NF.B.3c

4.NF.B.3d

5

1

8 ··

1

1

8 ··

1

1; 3

8 ·· 8 ··

5

4 ··

4.NF.B.4b

1

8 ··

1

2 ; 2 1 5 1 8 ·· 8 ··

4.NF.B.4c

1

1

8 ··

5

8

8 ··

1

8

8 ··

1

1.

8 ··

1 2

1 ·· 4 2

1 2

b ·

1

1

1 2

b ······


Content Emphasis


Express a fraction with denominator 10 as an equivalent fraction with denominator 100, and use this technique to add two fractions with respective denominators 10 and 100.4 For example, express 3 as 30 , and add 3 1 4 5 34 .

Major

20

Use decimal notation for fractions with denominators 10 or 100. For example, rewrite 0.62 as 62 ; describe a length as 0.62 meters; locate 0.62 on a number line diagram.

Major

21

Compare two decimals to hundredths by reasoning about their size. Recognize that comparisons are valid only when the two decimals refer to the same whole. Record the results of comparisons with the symbols ., 5, or ,, and justify the conclusions, e.g., by using a visual model.

Major

22

Know relative sizes of measurement units within one system of units including km, m, cm; kg, g; lb, oz.; l, ml; hr, min, sec. Within a single system of measurement, express measurements in a larger unit in terms of a smaller unit. Record measurement equivalents in a two-column table. For example, know that 1 ft is 12 times as long as 1 in. Express the length of a 4 ft snake as 48 in. Generate a conversion table for feet and inches listing the number pairs (1, 12), (2, 24), (3, 36), . . .


23

Use the four operations to solve word problems involving distances, intervals of time, liquid volumes, masses of objects, and money, including problems involving simple fractions or decimals, and problems that require expressing measurements given in a larger unit in terms of a smaller unit. Represent measurement quantities using diagrams such as number line diagrams that feature a measurement scale.


24, 25

Apply the area and perimeter formulas for rectangles in real world and mathematical problems. For example, find the width of a rectangular room given the area of the flooring and the length, by viewing the area formula as a multiplication equation with an unknown factor.


26


27

Common Core State Standards for Grade 4 — Mathematics Standards Number and Operations—Fractions (continued) Understand decimal notation for fractions, and compare decimal fractions. 4.NF.C.5

10 ··

4.NF.C.6

100 ···

10 ··

100 ···

100 ···

100 ···

4.NF.C.7

Measurement and Data Solve problems involving measurement and conversion of measurements. 4.MD.A.1

4.MD.A.2

4.MD.A.3

Represent and interpret data. 4.MD.B.4

Make a line plot to display a data set of measurements in fractions of a unit 1 , 1 , 1 . 2 ·· 4 ·· 8 ·· Solve problems involving addition and subtraction of fractions by using information presented in line plots. For example, from a line plot find and interpret the difference in length between the longest and shortest specimens in an insect collection.

1

2

Geometric measurement: understand concepts of angle and measure angles. 4.MD.C.5

Recognize angles as geometric shapes that are formed wherever two rays share a common endpoint, and understand concepts of angle measurement:


28

4.MD.C.5a An angle is measured with reference to a circle with its center at the common endpoint of the rays, by considering the fraction of the circular arc between the points where the two rays intersect the circle. An angle that turns through 1 of a circle is called a “one-degree angle,” and can 360 ··· be used to measure angles.


28

A44


Common Core State Standards for Grade 4 — Mathematics Standards

Content Emphasis


Measurement and Data (continued) Geometric measurement: understand concepts of angle and measure angles. (continued)

4.MD.C.5b An angle that turns through n one-degree angles is said to have an angle measure of n degrees.


28

4.MD.C.6

Measure angles in whole-number degrees using a protractor. Sketch angles of specified measure.


29

4.MD.C.7

Recognize angle measure as additive. When an angle is decomposed into nonoverlapping parts, the angle measure of the whole is the sum of the angle measures of the parts. Solve addition and subtraction problems to find unknown angles on a diagram in real world and mathematical problems, e.g., by using an equation with a symbol for the unknown angle measure.


30

Geometry Draw and identify lines and angles, and classify shapes by properties of their lines and angles. 4.G.A.1

Draw points, lines, line segments, rays, angles (right, acute, obtuse), and perpendicular and parallel lines. Identify these in two-dimensional figures.


31

4.G.A.2

Classify two-dimensional figures based on the presence or absence of parallel or perpendicular lines, or the presence or absence of angles of a specified size. Recognize right triangles as a category, and identify right triangles.


32

Recognize a line of symmetry for a two-dimensional figure as a line across the figure such that the figure can be folded along the line into matching parts. Identify linesymmetric figures and draw lines of symmetry.


33

4.G.A.3


Interim Assessment Correlations The tables below show the depth-of-knowledge (DOK) level for the items in the Interim Assessments, as well as the standard(s) addressed, and the corresponding Ready ® Instruction lesson(s) being assessed by each item. Use this information to adjust lesson plans and focus remediation.

Ready ® Common Core Interim Assessment Correlations Unit 1: Number and Operations in Base Ten, Part 1 Question

DOK1

Standard(s)

Ready ® Common Core Student Lesson(s)

1

1

4.NBT.A.3

4

2

1

4.NBT.A.2

1

3

1

4.NBT.B.4

3

4

1

4.NBT.A.2

1

5

1

4.NBT.A.2, 4.NBT.B.4

2, 3

6

2

4.NBT.A.1, 4.NBT.A.2

1

7

3

4.NBT.A.2, 4.NBT.A.3

2, 4

PT

3

4.NBT.A.1, 4.NBT.A.2, 4.NBT.A.3, 4.NBT.B.4

1, 2, 3, 4

Unit 2: Operations and Algebraic Thinking Question

DOK

Standard(s)


1

1

4.OA.B.4

7

2

2

4.OA.A.3

9

3

2

4.OA.A.3

9, 10

4

1

4.OA.C.5

8

5

2

4.OA.A.3

9, 10

6

2

4.OA.B.4

7

PT

3

4.OA.A.3, 4.OA.B.4, 4.NBT.B.4, 4.NBT.B.5

3, 7, 9, 10, 11

Unit 3: Number and Operations in Base Ten, Part 2 Question

DOK

Standard(s)


1

1

4.NBT.B.5

11

2

2

4.NBT.B.6

12

3

2

4.NBT.B.5

11

4

2

4.NBT.B.5

11

5

3

4.NBT.B.5

11

6

1

4.NBT.B.6

12

PT

3

4.NBT.B.4, 4.NBT.B.5, 4.NBT.B.6, 4.OA.A.3

3, 9, 10, 11, 12

1Depth of Knowledge levels:

1. The item requires superficial knowledge of the standard. 2. The item requires processing beyond recall and observation. 3. The item requires explanation, generalization, and connection to other ideas.



Ready ® Common Core Interim Assessment Correlations (continued) Unit 4: Number and Operations—Fractions Question

DOK

Standard(s)


1

1

4.NF.B.4b

18

2

1

4.NF.C.5

20

3

2

4.NF.B.3

15, 16

4

2

4.NF.A.2

14

5

2

4.NF.A.1

13

PT

3

4.NF.B.3, 4.NF.B.4, 4.NBT.B.5, 4.NBT.B.6

11, 12, 15, 16, 18, 19

Unit 5: Measurement and Data Question

DOK

Standard(s)


1

1

4.MD.C.7

30

2

2

4.MD.A.1

23

3

1

4.MD.A.3

26

4

2

4.MD.A.1

23

5

1

4.MD.C.5a

28

PT

3

4.MD.A.1, 4.MD.A.2, 4.OA.A.2, 4.NF.B.3a

6, 15, 16, 23, 24, 25

Unit 6: Geometry Question

DOK

Standard(s)


1

1

4.G.A.3

33

2

1

4.G.A.2

32

3

2

4.G.A.2, 4.G.A.3

32, 33

4

2

4.G.A.3

33

5

1

4.G.A.2

32

6

2

4.G.A.3

33

PT

3

4.G.A.1, 4.G.A.2, 4.G.A.3

31, 32, 33

©Curriculum Associates, LLC


A47

Focus on Math Concepts

Lesson 15

(Student Book pages 136–141)


LESSON OBJECTIVES

THE LEARNING PROGRESSION

• Understand addition as joining parts.

One goal of the Common Core is to develop a deeper understanding of fractions by using a progression of concepts from simple to complex. This lesson prepares students for the conceptual shift involved in progressing from adding and subtracting whole numbers to adding and subtracting fractions. Students are guided to think of operations with fractions as very much like operations with whole numbers.

• Understand subtraction as separating parts. • Extend their understanding of addition and subtraction of whole numbers to addition and subtraction of fractions. • Use fraction models to add and subtract fractions with like denominators.

Students see that you can count with unit fractions

PREREQUISITE SKILLS

just as you count with whole numbers. And because

In order to be procient with the concepts in this lesson, students should:

you can count with unit fractions, you can also do arithmetic with them. If you walked 2 of a

5 ·· 4 mile (2 fths) yesterday and of a mile (4 fths) today, 5 ·· altogether you walked 6 of a mile (6 fths; because 5 ··

• Know addition and subtraction basic facts. • Understand the meaning of fractions. • Identify numerators and denominators.

2 things plus 4 more of those things is 6 of those

• Write whole numbers as fractions.

things).

VOCABULARY

Students use the meaning of fractions and the meanings of addition and subtraction that were built in earlier grades to understand why the procedures for adding and subtracting fractions make sense.

There is no new vocabulary. Review the following key terms. numerator: the

top number in a fraction; it tells the number of equal parts that are being described

Teacher Toolbox

denominator: the

bottom number in a fraction; it tells the total number of equal parts in the whole

Ready Lessons

Teacher-Toolbox.com

Prerequisite Skills

4.NF.B.3a 4.NF.B.3b

✓✓

✓

Tools for Instruction

✓

Interactive Tutorials

✓

CCSS Focus 4.NF.B.3 Understand a fraction a with a . 1 as a sum of fractions 1 . · b

b ··

a. Understand addition and subtraction of fractions as joining and separating part s referring to the same whole. b. Decompose a fraction into a sum of fractions with the sa me denominator in more than one way, recording each decomposition by an equation. Justify decompositions, e.g., by using a visual fraction model. STANDARDS FOR MATHEMATICAL PRACTICE: SMP 1–8 (See page A9 for full te xt.)

150

L15: Understand Fraction Addition and Subtraction



Part 1: Introduction

Lesson 15

AT A GLANCE

Focus on Math Concepts

Students explore the idea that adding fractions is not essentially different from adding whole numbers.

Lesson 15


CCSS 4.NF.B.3a


4.NF.B.3b

A number line diagram gives meaning to the What’s really going on when we add numbers?

expression 2 1 3 . 4 ··

4 ··

Adding means joining or putting things together. Think about how you could explain adding 2 1 3 to a first grader. You could start at 2, count on 3 more, and see where you end up: 2 . . . 3 . . . 4 . . . 5.

STEP BY STEP

Or, you could put a segment with a length of 2 and a segment with a length of 3 next to each other on a number line to show 2 1 3.

• Introduce the Question at the top of the page.

1

• Help students relate the number line diagram to the sum 2 1 3.

0

1

1

1

2

1

3

1

4

5

6

7

8

9

10

When you add 2 1 3, you are putting ones together.

• Read Think with students. Reinforce the idea that fractions are numbers.

Think Adding fractions means joining or putting together part s of the same whole.

• Guide students to recognize that just as the

You can put a segment with a length of 2 and a segment 4 ··

Underline the sentence that explains what adding fractions means.

with a length of 3 next to each other to show 2 1 3 .

number 5 is made up of 5 ones, the number 5 is 4 ··

4 ··

1

1

4

made up of 5 one-fourths.

• If students need additional support with locating

4 ··

1

4

1

4

4

4

0

1

2

3

4

5

6

7

4

4

4

4

4

4

4

4

0

4 ··

1

1

8 4

2

When you add 2 1 3 , you are putting one-fourths together.

fractions on a number line, have them build a

4 ··

4 ··

number line by putting 1 fraction strips end-to-end, 4 ··

creating a concrete model to show 2

4 ··

1

3.

136

4 ··


Concept Extension • Draw and label a number line on the board from 0 to 2 like the one on the page showing fourths. • Ask students to think of two different fractions that you could put together that would give you the same sum as adding 2 and 3 . 4 ··

• Have a volunteer go to the board to show the

3 ·· 4

two fractions on the number line. 1 and 4 in either order

4




Mathematical Discourse

To extend students’ understanding of decomposing fractions, follow these steps:

4 ··

L15:Understand Fraction Addition and Subtraction


4 ··

• How would you explain adding in your own words? Responses should include phrases such as “join” or “put together.” • How is adding fractions like adding whole numbers? Students may mention that, in both cases, you are putting things together. • Can you think of another way to explain adding fractions? Students may suggest that you can count on with fractions just like you count on with whole numbers.

151


Lesson 15

AT A GLANCE Students explore the idea that subtracting fractions is not essentially different from subtracting whole numbers. A number line diagram gives meaning to the expression 5 2 2 . 4 ··

4 ··


Think Subtracting means separating or taking away.

0

students who need more support.

• Have students read and reply to the Reect directive.

the numerators of the

1

1

1

2

1

1

1

1

3

4

connection.

5

6

7

8

9

10

When you subtract 5 2 2, you are taking away ones. You can show subtracting fractions on a number line. Start with a segment of length 5 and take away a segment of length 2 to show 5 2 2 . 4 ··

• Ask a volunteer to explain how to use the number line to find 5 2 2 . Provide 1 fraction strips for 4 ·· 4 4 ·· ··

numbers. Now look at

fractions. I think I see a

STEP BY STEP • Discuss how the number line represents the problem 5 2 2. Show how to subtract on the number line. (start at 5 and count back 2)

Look at the whole

On a number line, you can start with a segment of length 5 and take away a segment of length 2 to show 5 2 2.

1

• Read Think with students.

Lesson 15

4 ··

1

1

4

4

1

1

1

1

1

4

4

4

4

4

0

1

2

3

4

4

4

4

0

4 ··

4

5

6

7

4

4

4

4

1

4 ··

8 4

2

When you subtract 5 2 2 , you are taking away one-fourths. 4 ··

4 ··

Now you’ll have a chance to think more about how adding or subtracting fractions is like adding or subtracting whole numbers. You may find that using number lines or area models can help you explain your thinking.

Reflect

Visual Model • Tell students that you will use a number line to show 5 2 3 . 8 ··

8 ··

1

Use your own words to describe what you just learned about adding and subtracting fractions. Possible answer: I learned that adding and subtracting fractions is just like adding and subtracting whole numbers. When the denominators are the same, you can just add or subtract the numerators. 137



• Draw a number line from 0 to 1 on the board. • Ask students for ideas on how to divide the line so that you can use it to help you solve the problem. • Have students explain why dividing the line into eighths makes sense. • Label 0 and 1 on the line and have students provide labels for the other marks as you move your finger along the line. • Ask a volunteer to show how to nd the answer to the problem using the number line.

SMP Tip: In the Visual Model activity, students are asked to reason quantitatively and explain why dividing the line into eighths makes sense. (SMP 2)

152

Mathematical Discourse • How would you explain subtracting in your own words? Listen for phrases such as “take apart” or “take away.” • How is subtracting fractions like subtracting whole numbers? Students may note that subtracting means taking away. It doesn’t matter what kinds of numbers you’re subtracting. • Do you see a connection between the whole numbers and the numerators of the fractions on this page? Students may mention that the whole numbers and the numerators of the fractions are the same numbers, and to answer both problems you subtract 2 from 5.




Part 2: Guided Instruction

Lesson 15

AT A GLANCE Part 2: Guided Instruction

Students use number lines to answer questions, reinforcing the understanding that fractions are numbers.

Lesson 15

Explore It Counting on and using a number line ar e two ways to think about adding fractions. 3

2

STEP BY STEP

0

3

STUDENT M ISCONCEPTION A LERT: Some

students may think that a fraction is always less than 1. If this misconception persists, use fraction strips to demonstrate fractions less than, equal to, and greater than 1. Then, encourage students to use the fraction strips to show and name other fractions greater than 1.



8

9

1

2

4

4

3 4 ··

4

5

4

4

6 4 ··

7 4 ··

8 4 ··

9 4 ··

10 4

3 4 5 Count by fifths to fill in the blanks: 1 , 2 , ·· 5 , ·· 5 , ·· 5 5 ·· 5 ··

0

1

2

5

5

3 5 ··

4 5 ··

5 5 ··

6 5

Use the number lines above to answer numbers 4 and 5. 4

What is 1 more than 6 ?

5

What is 1 more than 3 ?

4 ··

4 ··

5 ··

5 ··

7 4 ·· 4 5 ··

Now try these two problems. 6

• If students need more support, suggest that they count out loud to help them ll in the missing numbers in problems 2 and 3.

• Take note of students who are still having difculty and wait to see if their understanding progresses as they work in their groups during the next part of the lesson.

7

4 ·· 4 ··

Now label the number line.

• As students work individually, circulate among them. This is an opportunity to assess student understanding and address student misconceptions. Use the Mathematical Discourse questions to engage student thinking.

5 ··

4 ·· 4 ··

Now label the number line.

• Tell students that they will have time to work individually on the Explore It problems on this page and then share their responses in groups. You may choose to work through the rst problem together as a class.

• To help students answer problem 4, have them put their nger on 6 on the number line, then count on 4 ·· by 1 . Similarly, to answer problem 5, have them put 4 ·· their nger on 3 on the number line and count on 5 ·· by 1 .

6

4 5 Count by fourths to fill in the blanks: 1 , 2 , ·· 4 , , , ·· 4 , ·· 4 , ·· 4 , ·· 4

7

138

Label the number line below and use it to show 2 1 1 . 4 ··

4 ··

0

1

2

3

4

5

6

7

8

4

4

4

4

4

4

4

4

4

Label the number line below and use it to show 3 1 1 . 4 ··

4 ··

0

1

2

3

4

5

6

7

8

4

4

4

4

4

4

4

4

4




Mathematical Discourse • In which direction on the number line do you move when adding? Explain. Responses might include the fact that adding means joining so you will be getting segments that are longer or an answer farther to the right than the number you started with. • For problem 5, will the answer change if you find 3 more than 1 ? Explain. 5 ··

5 ··

Listen for responses that demonstrate an understanding that you can add two numbers in any order and get the same sum.

153


Lesson 15

AT A GLANCE Students use number lines to show subtracting fractions. Then they use models to show adding and subtracting fractions.


Lesson 15

Talk About It Solve the problems below as a group. 8

STEP BY STEP

Look at your answers to problems 2 and 3. How is counting by fractions the same as counting with whole numbers? Possible answer: When you count with whole numbers, you count by ones. When you count with fractions, the numerator counts by ones as long as the denominators are the same.

• Organize students in pairs or groups. You may choose to work through the first Talk About It problem together as a class. • Walk around to each group, listen to, and join in on discussions at different points. Use the Mathematical Discourse questions to help support or extend students’ thinking.

How is it different? Possible answer: When you count by fractions, you are counting by parts.

9

2 2 . Label the number line below and use it to show 7 8 8 ··

0

10

• When shar ing ideas about problems 9 and 10, be sure to emphasize that when labeling the number line, numerators count on by ones, but the denominator remains the same.

1

2

3

4

5

6

7

8

9

10

11

12

8

8

8

8

8

8

8

8

8

8

8

8

1 2 . Label the number line below and use it to show 5 6 6

SMP Tip: During this time, you may choose to ask a particular group to prepare to share their thinking or solution. Encourage students to critique the group’s reasoning, especially if it shows a different way to show or think about one of the problems or shows a misconception that surfaced during the group work time. (SMP 3)

··

0

··

··

1

2

3

4

5

6

7

8

9

10

11

12

6

6

6

6

6

6

6

6

6

6

6

6

Try It Another Way Work with your group to use the area models to show adding or subtracting fractions. 11

Show 1 1 2 . 8 ··

12

8 ··

Show 6 2 2 . 10 ·· 10 ··

139




• Direct the group’s attention to Try It Another Way. Have a volunteer from each group come to the board to draw the group’s solutions to problems 11 and 12.

Hands-On Activity Use fraction strips to subtract fractions. Materials: strips

of paper, markers, scissors

• Model how to fold the strip of paper in half, in half again, and in half a third time. Tell students to unfold the strips and use a marker to show the 8 equal sections. • Direct students to cut out each section. Ask them to name the fraction that represents each section.

3 4

1 Have them label each section. 8 ·· • Write 7 2 5 on the board. Have students use their 8 ·· 8 ·· strips to show that the difference is 2 . 8 ··

154

Mathematical Discourse • What is another name for 8 ? 12 ? Explain your 8 ·· 6 ·· thinking. Students should recognize that eight 1 pieces 8 ··

make up 1 whole and that twelve 1 pieces make 6 ··

up 2 wholes.

• Can you think of another way to show finding a difference on a number line? Students may mention adding up to subtract. For example, to nd 7 2 2 , you might start 8 ··

8 ··

at 2 and think, “What do I need to add to 8 ··

get to 7 ?” 8 ··




Part 3: Guided Practice

Lesson 15

AT A GLANCE Part 3: Guided Practice

Students demonstrate their understanding of adding and subtracting fractions as they talk through three problems.

Lesson 15

Connect It Talk through these problems as a class, then write your answers below. 13

STEP BY STEP

Compare: Draw two different models to show 2 2 1 . 3 ··

3 ··

Possible answers:

• Discuss each Connect It problem as a class using the discussion points outlined below.

0

14

1

2

3

3

3

3

Explain: Rob had a large pizza and a small pizza. He cut each pizza into fourths. He took one fourth from each

Compare:

pizza and used the following problem to show their sum: 1 1 1 5 2 . 4 ··

• You may choose to have students work in pairs to encourage sharing ideas. Each partner draws a different model.

4 ··

Possible answer: Rob’s addition is correct, but he cannot add one fourth of the large pizza and one fourth of the small pizza in this way because the wholes are not the same.

• For a quick and easy assessment, have students draw their models on small whiteboards or paper and hold them up. Choose several pairs to explain their models to the class. • Use the following to lead the class discussion: Explain how you knew the number of parts to draw in the whole. How did you show subtraction in your model? How are the models the same? How are they different?

4 ··

What did Rob do wrong?

15

Demonstrate: Think about how you would add three whole numbers. You add two of the numbers first, and then add the third to that sum. You add three fractions the same way. 1 1 3 1 4. Use the number line and area model below to show 10 10 ·· 10 ·· ··

0

140

1

2

3

4

5

6

7

8

9

10

10

10

10

10

10

10

10

10

10

10




Demonstrate: Explain:

• The second problem focuses on the importance of the whole and the fact that you cannot add or subtract fractions unless they refer to the same whole. • Read the problem together as a class. Ask students to continue to work in pairs to discuss and write their responses about what Rob did wrong. • Begin the discussion by asking questions, such as: What fraction describes a slice of the larger pizza?

3 ·· 14 4 What fraction describes a slice of the smaller pizza? 3 1 4 4 ··

Are both 1 s the same size? [no] Why not? [the whole 4 ··

• This discussion gives students an opportunity to think about problems that involve adding three fractions.

SMP Tip: Ask students to show how to use a number line as a tool to model the sum of three whole numbers. (SMP 5)

• Discuss how you can add three (or more) fractions in the same way as adding whole numbers as long as you are talking about the same type of fractions. Have students explain how they used the models to show the sum. • Remind students to start at 0 when labeling the number line.

pizzas are not the same size]

Why doesn’t it make sense to a dd these two fractions? [the wholes are not the same]




155

Part 4: Common Core Performance Task

Lesson 15

AT A GLANCE Part 4: Common Core Performance Task

Students write two questions that can be answered using some or all of the given information about the problem situation. Then they answer one of the questions.

Lesson 15

Put It Together 16

Use what you have learned to complete this task.

Jen has 4 of a kilogram of dog food. Luis has 3 of a kilogram of dog food. 10 10 ·· ·· A large dog eats 2 of a kilogram in one meal. 10 ··

STEP BY STEP

A Write two different questions about this problem that involve adding or subtracting fractions.

• Direct students to complete the Put It Together task on their own.

i Possible answer: How much dog food do Jen and Luis have altogether?

ii Possible answer: How much more dog food does Jen have than Luis?

• Explain to students that the questions they write do not have to use all of the given information.

B Choose one of your questions to answer. Circle the question you chose. Show how to find the answer using a number line and an area model. Possible answers:

• As students work on their own, walk around to assess their progress and understanding, to answer their questions, and to give additional support, if needed.

0

• If time permits, have students share one of their questions with a partner and show how to find the answer to their partner’s question using a visual model.

1

2

3

4

5

6

7

8

9

10

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10

10

10

10

10

10

10

10

10

4 10 ···

1

3 10 ···

SCORING RUBRICS L15:Understand Fraction Addition and Subtraction

See student facsimile page for possible student answers. A

141


Points Expectations

2

156


The response demonstrates the student’s mathematical understanding of adding and subtracting fractions. Both questions can be answered using the information given in the problem.

1

An effort was made to accomplish the task. The response demonstrates some evidence of verbal and mathematical reasoning, but the student’s questions may contain some misunderstandings.

0

There is no response or the response shows little or no understanding of the task.

B

Points Expectations

2

Both a number line and an area model are correctly drawn and labeled to show the solution to the problem.

1

Only one model is correctly drawn and labeled or the models drawn may contain minor errors. Evidence in the response demonstrates that with feedback, the student can revise the work to accomplish the task.

0

There are no models drawn or the models show no evidence of providing visual support for solving the problem.




Differentiated Instruction

Lesson 15

Intervention Activity

On-Level Activity

Use fraction strips to model adding and subtracting fractions.

Decompose fractions in more than one way.

Materials: fraction strips

In this activity, students think of multiple ways to decompose fractions.

Write an addition expression on the board, such as

Write the fraction 6 on the board. Ask students to 5 ··

2 1 3 . Have students lay 1 fraction strips end-to-end 8 ·· 8 8 ·· ··

think about 6 as a sum. Ask them to find at least four

1 s there are in all. Continue with similar problems. 8 ··

number lines, area models, or fraction strips for

Include expressions whose sums are greater than

students to use.

one, such as 3

Provide at least one example: 6 5 1

5 ··

ways they can put fifths together to make 6 . Provide

to show the sum. Ask them to tell you how many

4 ··

1

5 ··

2.

4 ··

5 ··

as 5 2 2 . Have students lay 1 fraction strips end-to6 ··

6 ··

6 ··

6 ··

6 ·· 1 them to tell you how many s are left. Continue with 6 ··

similar problems. Be sure to provide expressions that include fractions greater than one, such as 6 2 3 . 5 ··

5 ··

1

1

5 ··

1

2

5 ··

1

2

5 ··

Note the methods students use. Are they systematic or do they just guess and check their answers? Do they find more than four ways?

Write a subtraction expression on the board, such end to show 5 . Then have them “take away” 2 . Ask

5 ··

If time permits, give students (or pairs or groups) practice decomposing other fractions, such as 5 or 8 ·· 5 . This activity also gives students practice writing 10 ·· number sentences.

Challenge Activity Write a question for the answer given. Write the following problem on the board: The answer is 7 . What could the question be? 8 ··

Encourage students to think about both addition and subtraction. Provide number lines, area models, or fraction strips for support as necessary. Note the methods students use. Do they just guess, work out their problem, check to see if it’s correct, and then adjust their responses if necessary? Do they use a visual model or do they work symbolically? If time permits, give students (or pairs or groups) practice with similar problems. You might ask them to write two questions for each answer you supply, one using addition and one using subtraction.




157

Develop Skills and Strategies

Lesson 16

(Student Book pages 142–151)

Add and Subtract Fractions LESSON OBJECTIVES

THE LEARNING PROGRESSION

• Add fractions with like denominators.

In keeping with the Common Core goal of developing a deeper understanding of fractions, this lesson extends students’ understanding of fraction addition and subtraction. Students use visual models and equations to represent and solve word problems involving the addition and subtraction of fractions referring to the same whole and having like denominators.

• Subtract fractions with like denominators. • Use fraction models, number lines, and equations to represent word problems.

PREREQUISITE SKILLS In order to be procient with the concepts/skills in this lesson, students should:

Teacher Toolbox

• Understand addition as joining parts. • Understand subtraction as separating parts.

Ready Lessons

• Know addition and subtraction basic facts. • Understand the meaning of fractions.

Tools for Instruction

• Identify numerators and denominators.

Interactive Tutorials

Teacher-Toolbox.com

Prerequisite Skills

4.NF.B.3a 4.NF.B.3d

✓✓

✓

✓

✓ ✓

• Write whole numbers as fractions. • Compose and decompose fractions.

VOCABULARY There is no new vocabulary. Review the following key terms. numerator: the

top number in a fraction; it tells the number of equal parts that are being described denominator: the

bottom number in a fraction; it tells the total number of equal parts in the whole

CCSS Focus 4.NF.B.3 Understand a fraction a with a . 1 as a sum of fractions 1 . b ·

b ··

a. Understand addition and subtraction of fractions as joining and separating part s referring to the same whole. d. Solve word problems involving addition and subtraction of fractions referring to the same whole and having like denominators, e.g., by using visual fraction models and equations to represent the problem. STANDARDS FOR MATHEMATICAL PRACTICE: SMP 1, 2, 4, 5, 6, 7, 8 (See page A9 for full te xt.)

158

L16: Add and Subtract Fractions




Lesson 16

AT A GLANCE Students read a word problem and answer a series of questions designed to explore the connection between adding and subtracting fractions and adding and subtracting whole numbers.

Develop Skills and Strategies

Lesson 16


CCSS 4.NF.B.3a

Add and Subtract Fractions

4.NF.B.3d

In Lesson 15, you learned that adding fractions is a lot like a dding whole numbers. Take a look at this problem.

STEP BY STEP

Lynn, Paco, and Todd split a pack of 12 baseball cards. Lynn got 4 cards, Paco got 3 cards, and Todd got the rest of the cards. What fraction of t he pack did Todd get?

• Tell students that this page models building the solution to a problem one step at a time and writing to explain the solution. • Have students read the problem at the top of the page.

Explore It

• Work through Explore It as a class.

Use the math you already know to solve the problem.

How many cards did Todd get?

5

There are 12 cards in the pack. What fraction represents the whole pack of cards? 12

12 ···

If Lynn got 4 cards out of 12, that means she got 4 of the pack. If Paco got 3 cards ·· 12 3 out of 12, what fraction of the pack did he get? 12 ···

• Guide students to understand th at they needed to “join” and “take away” the numbers of cards to answer the questions. • Be sure to point out that 4 1 3 1 5 equals the total number of cards, 12. Remind students that the whole is represented by the set, or pack, of cards.

7

How many cards did Lynn and Paco get altogether?

• Ask students to explain how they gured out the answers for how many cards Lynn and Paco received altogether, and for how many cards Todd received.

What fraction of the pack did Lynn and Paco get altogether?

7

12 ···

Explain how you could find the fraction of the pack that Todd got. Possible answer: Todd got 5 cards. There are 12 cards in the pack. If the numerator tells the number of cards Todd got, and the denominator tells the number of cards in the pack, then Todd got 5 of the pack. 12 ···

142

L16:Add and Subtract Fractions



• Ask student pairs or groups to explain their answers for the remaining questions. • Encourage students to explain the connection between adding and subtracting fractions and whole numbers. [When adding or subtracting whole numbers, you join or separate whole numbers. And, when adding or subtracting fractions, you join or separate parts of a set or whole.]



Mathematical Discourse • What does the denominator of a fraction tell you? Listen for responses that include the phrase “equal parts of a whole” or “equal parts of a set.” • What does the numerator of a fraction tell you? Students’ responses should indicate an understanding that the numerator tells you the number of equal parts you are talking about.

159


Lesson 16

AT A GLANCE Students use fraction models to review adding and subtracting fractions.


Lesson 16

Find Out More We often use fractions in real life. Sometimes they refer to parts of a set of objects, like the baseball card problem. In that problem, the “whole” is the pack, and 12 cards means there are 12 parts of the whole.

STEP BY STEP • Read Find Out More as a class. • Point out that when you have a set of objects, t he denominator represents the total number of objects in the set. Since there are 12 baseball cards in the pack, that means there are 12 parts in the set. The number of cards that each person has represents the numerator of the fraction. • Remind students that when you have a whole object that is divided into equal parts, the denominator shows the total number of parts. • Note that the whole pizza was divided into 8 equal slices, so the denominator is 8. If there are 7 slices remaining, then the numerator of the fraction is 7. If 2 more slices are taken away, then there are 5 slices left, and the numerator of the fraction is 5.

Each person got baseball cards from the same pack, so each fraction refers to the same whole. When you add or subtract baseball cards, the whole will stay the same because the cards are all from the same pack of 12.

4

3

5

12

12

12

Fractions in real life can also refer to equal parts of a whole object. Lynn, Paco, and Todd might share a pizza cut into 8 slices. The “whole” is the pizza, and 8 slices means there are 8 equal parts of the whole. Even if a person takes away 1 slice or 3 slices from the pizza, the whole will stay the same.

Reflect 1

Describe another example of a set of objects or a whole object divided into fractions. Possible answer: You can think of a full egg carton as a set of objects. Each egg is 1 of the set. 12 ···

• Have students read and reply to the Reect directive. 143



Hands-On Activity Use models to add fractions. Materials: Drawing

paper and notebook paper

• Distribute drawing paper and a piece of notebook paper to each student. Tell students to use scissors to cut out 12 equal-sized cards. Explain to students that the 12 cards represent one pack of cards, or one whole set, and that there are 12 parts in the set.

Real-World Connection Encourage students to think about everyday places or situations where people might need to add or subtract like fractions. Have volunteers share their ideas. Examples: cooking, construction site, distances on a map

• Tell students to hold up 2 cards. Have students write the name of the fraction represented by the 2 cards on their paper. Review the meaning of the fraction. [2 cards out of 12] Then, repeat with 7 cards. • Tell students to add (join) the fractions and wr ite the sum on their paper. Have a volunteer explain how they determined their answer. • If time permits, repeat for additional fraction pairs.

160




Part 2: Modeled Instruction

Lesson 16

AT A GLANCE Part 2: Modeled Instruction

Students use models and number lines to review adding fractions.

Lesson 16

Read the problem below. Then explore different ways to understand it.

Josie and Margo made 10 clay pots in art class. Josie painted 3 of the pots. 10 ·· Margo painted 4 of the pots. What fraction of the clay pots did they paint? 10 ··

STEP BY STEP • Read the problem at the top of the page as a class.

Picture It You can use models to help understand the problem.

• Read Picture It. Have a volunteer name the

The following model shows the pots. Each pot is 1 of the total number of pots. 10 ··

denominator of the fraction in the problem. [10] Point out that each pot is 1 of the total number 10 ·· of pots.

Josie painted 3 pots, and Margo painted 4 pots. They painted a total of 7 pots. J

J

J

J

J

J

M

M

1

• Guide students to recognize that since Josie

M

painted 3 of the pots and Margo painted 4 , the 10 10 ·· ·· picture is shaded to represent the number of pots

J

J

J

M

M

M

M

5

M

3 tenths

4 tenths

7 tenths

Model It You can also use a number line to help understand the problem.

each girl painted, 3 for Josie and 4 for Margo. Have

The following number line is divided into tenths, with a point at 3 . 10 ··

students count aloud to nd the sum.

0

1 10

2 10

3 10

4 10

5 10

6 10

7 10

8 10

9 10

1

Start at 3 and count 4 tenths to the right to add 4 . ·· ·· 10 10

• Direct students to look at the number line in Model It. Emphasize that the number line is divided into tenths to represent the total number of pots.

0

1

2

3

4

5

6

7

8

9

10

10

10

10

10

10

10

10

10

1

• You may wish to draw the number line on the board 144

and have a volunteer demonstrate the 4 jumps to the




right to add 4 tenths to 3 . 10 ··

SMP Tip: Help students make sense of the problem and generalize that the same properties that apply to whole numbers apply to fractions. (SMP 1)

Mathematical Discourse • How could you use fractions to label 0 and 1 on the number line? Students may suggest that you can write both

Concept Extension Illustrate the commutative property of addition. • Ask, What if I drew the starting point at 4 instead 10 ·· of 3 ? Could I still solve the problem? 10 ··

as a number out of 10, so 0 and 10 . 10 10 ·· ·· • What is another way you could solve the problem? Responses may mention using fraction strips. You could line up three 1 strips and four 10 ·· 1 strips in a single row. Then, you could 10 ·· count how many tenths you have altogether.

• To emphasize the point, draw a number line on the board with a point at 4 . Then, have students 10 ·· explain how to count on from 4 to nd the 10 ·· answer. Encourage a volunteer to come to the board and demonstrate how to nd the sum.

161





Lesson 16


Students revisit the problem on page 144 to learn how to add fractions using equations. Then, students solve addition word problems.

Lesson 16

Connect It Now you will solve the problem from the previous page using equations. 2

STEP BY STEP

How do you know that each pot is 1 of the total number of pots? 10 ·· Possible answer: The denominator tells the total number of pots. The numerator tells the number of pots that you are talking about.

• Read Connect It as a class. Be sure to point out that the questions refer to the problem on page 144.

3

What do the numerators, 3 an d 4, tell you? Possible answer: 3 tells the number of pots that Josie painted. 4 tells the number of pots that Margo painted.

• Review the meanings of numerator (the number of equal parts of a set you have) and denominator (the total number of equal parts the set is divided into).

How many clay pots did Josie and Margo paint altogether?

5

Write equations to show what fraction of the clay pots Josie and Margo painted altogether. Use words:

6

3 4

would represent 1 of the pots? 1 8 ··

• If time allows, repeat with other fraction words.

5

4

5

10 ··

7 tenths 7 10 ····

Try It Use what you just learned to solve these problems. Show your work on a separate sheet of paper. 7

Lita and Otis are helping their mom clean the house. Lita cleaned 1 of the rooms. 3 ··

Otis cleaned 1 of the rooms. What fraction of the rooms did Lita and Otis clean 3 ··

8

ELL Support

• Have students write tenths and eighths on a piece of paper. Next to the words, have them write fractions associated with the words.

1

4 tenths

Explain how you add fractions with the same denominator.

altogether?

• Repeat using the word eighths.

3

10 ··

1

Possible answer: Add the numerators and leave the denominator as is.

• Emphasize that adding fractions is like adding whole numbers. Say, When finding the number of pots Josie and Margo painted altogether, you add the numerators of the fractions and write that sum over the denominator.

• Write the word tenths on the board. Circle the letters that spell ten in the word and write the number 10 below it.

3 tenths

Use fractions:

• Ask, If Josie and Margo only made 8 pots, what fraction

7

4

2 3 ··

Mark’s string is 1 of a meter long. Bob’s string is 3 of a meter long. How long are 5 ··

the two strings combined?

4 5 ··

5 ··

of a meter

145




TRY IT SOLUTIONS 7

Solution: 2 ; Students may show 1 on a number line 3 ··

3 ··

divided into thirds and count 1 mark to the right. They also may write the equation 1 1 1 5 2 . 3 ··

8

3 ··

3 ··

Solution: 4 of a meter; Students may show 1 on a 5 ··

5 ··

number line divided into fths and count 3 marks to the right. They also may write the equation 1 1 3 5 4. 5 ·· 5 ·· 5 ·· ERROR ALERT: Students

(

10 ··

both the numerators and the denominators.

162

)

who wrote 4 or 2 added 5 ··




Part 3: Modeled Instruction

Lesson 16

AT A GLANCE Part 3: Modeled Instruction

Students use models and number lines to review subtracting fractions.

Lesson 16

Read the problem below. Then explore different ways to understand it.

Alberto’s water bottle had 5 of a liter in it. He drank 4 of a liter. What fraction 6 ··

STEP BY STEP

6 ··

of the bottle still has water in it?

• Read the problem at the top of the page as a class.

Picture It You can use models to help understand the problem.

• Read Picture It. Guide students to recognize that Alberto’s water bottle is divided into 6 equal parts. Ask, What do the 6 equal parts represent? (the denominator) What do the 5 shaded parts represent? (the numerator, or how much water is in the bottle)

The following model shows the water bottle divided into 6 equal parts. Each part is 1 of a liter. Five shaded parts show how much water is in the bottle. 6 ··

Alberto drank 4 parts of the water in the bottle, so take away 4 shaded parts of the bottle. There is 1 part of the bottle left with water in it.

• Point out that 4 sixths are being taken away since Alberto drank 4 parts of the water bottle. Ask, What is 5 2 4? [1] Say, So, 1 sixth of Alberto’s water bottle still has water in it.

2

5

5 sixths

4 sixths

1 sixth

Model It

• Tell students to look at the number line in Model It. Point out that the number line is divided into sixths to represent the 6 equal parts of Alberto’s water bottle.

You can use a number line to help understand the problem. The following number line is divided into sixths, with a point at 5 . 6 ··

0

6 ··

3 4

name] land on? 1 Say, So, both the model and number 6 ··

2 6

3 6

4 6

5 6

1

Start at 5 and count 4 sixths to the left to subtract 4. 6 6 ·· ··

• Have a volunteer count 4 jumps to the left from 5 to subtract 4 sixths. Ask, What number did [volunteer’s

1 6

0

146

1 6

2 6

3 6

4 6

5 6

1




line show that 1 sixth of Alberto’s water bottle still has water in it.

Concept Extension Help students see the relationship between the picture and the number line. • Draw the number line on the board. Then, draw the 5 -full water bottle turned on its side above the 6 ·· number line, making sure each part of the water bottle is lined up with its tick mark on the number line. • Point out that 5 on the number line lines up with 6 ·· the top of the water bottle.

Mathematical Discourse • What is the difference between adding fractions and subtracting fractions on a number line? Responses may indicate direction, moving to the right to add and moving to the left to subtract. • What is another way to solve this problem? Students may mention using fraction strips or writing an equation.

• Then, cross out (or erase) one part of the water bottle at a time, moving from right to left along the number line. After 4 parts are crossed out (or erased) to show the water Alberto drank, point out to students that the remaining water is lined up with the 1 -mark on the number line. 6 ··



163


Lesson 16


Students revisit the problem on page 146 to learn how to subtract fractions using equations. Then, students solve subtraction word problems.

Lesson 16

Connect It Now you will solve the problem from the previous page using equations. 9

STEP BY STEP

How do you know that each part is 1 of a liter? 6 ··

Possible answer: The denominator tells the number of equal parts the bottle is divided into. The numerator tells the number of parts you are talking about.

• Read page 147 as a class. Be sure to point out that Connect It refers to the problem on page 146.

10

What do the numerators, 5 an d 4, tell you? Possible answer: 5 tells the number of parts that have water. 4 tells the number of parts that Alberto drank.

SMP Tip: Discuss with students how important it is to communicate clearly and precisely by reviewing the meanings of numerator (the number of equal parts you’re talking about) and denominator (the total number of equal parts in the whole). Ask, If Alberto’s water bottle was divided into 3 equal parts, what fraction would represent 1 of those parts? 1 (SMP 6)

11

How many parts of water are left in the bottle after Alberto drank 4 parts?

12

Write equations to show what fraction of the bottle has water left in it. Use words: Use fractions:

13

1 sixth

5

1

4

5

6 ··

6 ····

Explain how you subtract fractions with the same denominator.

Use what you just learned to solve these problems. Show your work on a separate sheet of paper. 14

Hands-On Activity Use paper plates to subtract fractions.

• Direct students to color 5 of the plate and then 8 ··

cut out that fraction of the plate. Ask students to

3 ·· 8 4

15

• Ask students to name the fraction of the plate

4 ··

4 ··

1 4 ··

Carmen had 8 of the yard left to mow. She mowed 5 of the yard. What fraction 10 10 ·· ·· 3 of the yard is left to mow? 10 ···

147




TRY IT SOLUTIONS 14

Solution: 1; Students may show 3 on a number line 4 ··

4 ··

divided into fourths and count 2 marks to the left. They also may write the equation 3

4 ··

ERROR ALERT: Students

2

2

4 ··

( ( )

5

who wrote 2 or 1

15

4 ··

1.

4 ··

)

2 ·· 4 subtracted from a full carton of eggs rather than 4 ·· the 3 of a carton that Mrs. Kirk had. 4 ··

name the fraction of the plate they have. 5

• Tell students to subtract 2 more eighths. Guide students to cut 2 more sections from the color portion of the plate they are holding.

Mrs. Kirk had 3 of a carton of eggs. She used 2 of the carton to make breakfast. What fraction of the carton of eggs does Mrs. Kirk have left?

plates, markers, rulers, scissors

• Distribute paper plates, markers, and scissors to each student. Model how to use the ruler to divide the plate into 8 equal sections. Students should draw 4 lines.

• Write 5 8 ··

2

4 sixths

Try It

• Remind students that subtracting fractions is like subtracting whole numbers. Say, When finding the number of parts of the water bottle that still have water, you subtract the numerators of the fractions and write the difference over the denominator.

they are

5

6 ··

2

Possible answer: Subtract the numerators and leave the denominator as is.

3 ·· 3 4

Materials: paper

5 sixths

1

Solution: 3 ; Students may show 8 on a number 10 ··

10 ··

line divided into tenths and count 5 marks to the left. They also may write the equation 8

2

5

5

3

10 ·· 10 ·· 10 ··

.

3 4

left with. 3 8 ·· 2 3 on the board. 8 ·· 8 ··

2

5

• If time allows, repeat for other subtraction problems.

164





Lesson 16


Lesson 16


Jessica hiked 2 mile on a trail before she stopped to get a drink

Mr. Chang has a bunch of balloons. 3 of the balloons are red. 10 ·· 2 of the balloons are blue. What fraction of the balloons are 10 ·· neither red nor blue?

of water. After her drink, Jessica hiked another 2 mile. How far

Show your work.

Study the model below. Then solve problems 16–18.

17

Student Model

The student used labels and “jump” arrows to show each part of the hike on a number line. It is just like adding whole numbers!

5 ··

5 ··

did Jessica hike in all?

I think that there are at least two different steps to solve this problem.

Possible student work using a model:

Look at how you could show your work using a number line. r

before drink

r

b

b

2 5

1 5

0

Pair/Share

r

after drink 2 5

How else could you solve this problem?

Lesson 16

2 5

3 5

4 5

1

4 mile

5 Solution: ··

red

blue

neither red nor blue

3 10 ···

2 10 ···

5 10 ···

Pair/Share How is this problem different from the others you’ve seen in this lesson?

5

10 Solution: ···

What fraction represents the whole fruit smoothie?

16

Ruth made a fruit smoothie. She drank 1 of it. What fraction of the 3 ··

18

fruit smoothie is left?

Emily ate 1 of a bag of carrots. Nick ate 2 of the bag of carrots. 6 ··

To find the fraction of the bag Emily and Nick ate altogether, should you add or subtract?

6 ··

What fraction of the bag of carrots did Emily and Nick eat

Show your work.

altogether? Circle the letter of the correct answer. A

Possible student work using an equation: 3 3 ··

1 3 ··

2

B

2 3 ··

5

C D

1

6 ·· 1

3 ·· 3

6 ·· 3

12 ··

Rob chose D as the correct answer. How did he get that answer? Rob added both the numerators and the denominators.

Pair/Share How did you and your partner decide what fraction to start with?

148

Pair/Share Does Rob’s answer make sense?

2 of a smoothie

3 Solution: ··


149





AT A GLANCE

SOLUTIONS

Students use models, number lines, or equations to solve word problems involving addition and subtraction of fractions.

Ex

STEP BY STEP

A number line is shown as one way to solve the problem. Students could also solve the problem by drawing a model that is divided into fths and shading 4 sections (2 sections out of 5 plus 2 sections out of 5).

• Ask students to solve the problems individually and label fractions in their drawings.

16 Solution:

• When students have completed each problem, have them Pair/Share to discuss their solutions with a partner or in a group.

17

2 of a smoothie; Students could solve the

3 ··

problem by using the equation 3

2

1 3 ··

5

2 . (DOK 2) 3 ··

3 ·· 5 ; Students could solve the problem by Solution: 10 ··

drawing a picture of 10 balloons and labeling 3 as red and 2 as blue. (DOK 2) 18 Solution: C;

Rob added the numerators correctly, but he mistakenly added the denominators together, too. Explain to students why the other two answer choices are not correct: A is not correct because you are not subtracting 1 from 2 ; this is an addition problem. 6 ··

B is

6 ··

not correct because 1 is not equivalent to 3.

(DOK 3)



3 ··

6 ··

165

Part 5: Common Core Practice


Lesson 16

Solve the problems.

1

B C D

3


4

5 of a yard for a school project. He has 2 of a yard Liang bought some cloth. He used } } 8 8 left. How much cloth did Liang buy? A

2

Lesson 16

Lesson 16

Lucy and Margot are mowing the lawn. They divided the lawn into 8 equal sections. Lucy mowed 2 sections and Margot mowed 4 sections. Which model can be used to find the total fraction of the lawn they mowed? Circle the letter of all that apply. A B

3 } of a yard 8 7 }} of a yard 16 7 } of a yard 8 8 of a yard } 8

C 0

D 0

2 of t he cake, and her brother Carmela cut a cake into 12 equal-sized pieces. She ate }} 12 3 of t he cake. What fraction of the cake is left? ate }} 12 1 A }} of the cake 12 5 B }} of the cake 12 7 C }} of the cake 12 12 D }} of the cake 12 2 cup of milk, 1 cup of oil, and 1 cup of sugar. How much Lee’s muffin mix calls for } } } 3 3 3 more milk than oil does she need for the muffin mix?

5

1

2

3

4

5

6

7

8

8

8

8

8

8

8

1

2

3

4

5

6

7

8

8

8

8

8

8

8

1

9 of a bucket of blueberries. Cole picked 3 of the In all, Cole and Max picked }} }} 10 10 bucket of blueberries. What fraction of the bucket of blueberries did Max pick? Possible student work using a number line: Show your work. 0

1

2

3

4

5

6

7

8

9

10

10

10

10

10

10

10

10

10

Answer Max picked

6

6 10 ···

1

of the bucket of blueberries.

5 of the pizza. A pizza is cut into 8 equal slices. Together, Regan and Juanita will eat } 8 What is one way the girls could eat the pizza? R

Show your work.

1 cup 3 ··

1

R

Possible student work using a model:

J J

Answer Regan could eat

Juanita could eat

2 8 ·· 3 8 ··

J

of the pizza, and of the pizza.

Self Check Go back and see what you can check off on the Self Check on page 119. 150




AT A GLANCE Students add and subtract fractions to solve word problems that might appear on a mathematics test.

SOLUTIONS 1 Solution: C; Possible student work using an equation: 5 1 2 5 7 (DOK 1) 8 ·· 8 ·· 8 ·· 2 Solution: C; Possible student work using equations: 2 1 3 5 5 ; 12 2 5 5 7 (DOK 1) 12 ·· 12 ·· 12 ·· 12 ·· 12 ·· 12 ·· 3 Solution: 1 cup; Possible student work using 3 ·· an equation: 2 2 1 5 1 (DOK 1) 3 ·· 3 ·· 3 ··

166

151




4 Solution: A; The model shows 2 shaded in light gray 8 ·· for Lucy’s sections and 4 shaded in dark gray for 8 ··

Margot’s sections. The total shaded sections

represent the total fraction of the lawn they mowed. D; The number line starts at Margot’s fraction (4) 8 ·· and adds 2 for Lucy’s fraction, for a total of 6 . 8 8 ·· ·· (DOK 2)

5 Solution: 6 ; Possible student work using 10 ·· an equation: 9 2 3 5 6 (DOK 1) 10 ·· 10 ·· 10 ·· 6 Solution: Possible student work using equations: 0 1 5 5 5, 1 1 4 5 5, 2 1 3 5 5, 3 1 2 5 5, 8 ·· 8 ·· 8 ·· 8 ·· 8 ·· 8 ·· 8 ·· 8 ·· 8 ·· 8 ·· 8 ·· 8 ·· 4 1 1 5 5 , 5 1 0 5 5 (DOK 2) 8 ·· 8 ·· 8 ·· 8 ·· 8 ·· 8 ··

L16: Add and Subtrac t Fractions


Differentiated Instruction

Lesson 16

Assessment and Remediation • Ask students to nd 4 1 2 . 6 or 3 10 ·· 10 ·· 10 ·· 5 ·· • For students who are still struggling, use the chart below to guide remediation.

3

4

• After providing remediation, check students’ understanding. Ask students to explain their thinking while nding 2 1 3 . 5 or 1 5 ··

3

5 ·· 5 ··

4

• If a student is still having difculty, use Ready Instruction, Level 4, Lesson 15. If the error is . . .

Students may . . .

To remediate . . .

6

have added both the numerators and the denominators.

Remind students that the denominator tells the kind of par ts you are adding. Explain that just as 4 apples 1 2 apples 5 6 apples, 4 tenths 1 2 tenths 5 6 tenths.

3

have added numerators, added denominators, and then simplified.

Remind students that the denominator tells the kind of par ts you are adding. Explain that just as 4 apples + 2 apples = 6 apples, 4 tenths + 2 tenths = 6 tenths.

2

have subtracted the fractions.

Remind students to read the problem carefully to be sure they’re using the correct operation.

1 5 ··

have subtracted the fractions and simplified.

Remind students to read the problem carefully to be sure they’re using the correct operation.

20 ··

10 ··

10 ··

Hands-On Activity

Challenge Activity

Use fraction strips to add fractions.

Write a problem for a given sum.

Materials: strips of paper, markers

Tell students that the sum of two fractions is 2.

Distribute paper and markers to each student. Direct

However, the original fractions did not have

students to fold a strip of paper in half, and then in

denominators of 5. Challenge students to write a

half again. Tell them to unfold the strips and use the

fraction addition problem that has a sum of 52.

marker to show the 4 equal sections. Tell students to color 1 of the strip. Then have them color another 1 4 ··

of the strip. Write 1

4 ··

1

1 on the board. Challenge 4 ··

3

3 1 1 Possible answer: 10 10 ···

4

5 ··

··

···

4 ··

them to use their fraction strips to show that the sum is 2 or 1. If time allows, repeat for other 4 ··

2 ··

denominators by folding another strip of paper three or four times.



167

NOTES

NOTES

Common Core Math Grade 4 Fraction Addition Subtraction

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