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Contents Foreword by Steve Leinwand xxv Acknowledgments xxix How to Use This Resource xxxi Introduction xxxi Reference Tables Reproducibles xxxvi Video Clips by Chapter xxxvii Video Clips by Grade, Including Demographics xli INTRODUCTION: Why Fractions, Decimals, and Percentages? 1 Fractions Are a Critical Foundation in Mathematics 2 Evidence of Our Struggles (the Data from Research) 2 Why Do Students Struggle with Fractions, Decimals, and Percentages? 4 Mathematical Areas Linked to Students’ Difficulties with Fractions 4 Procedural Knowledge Linked to Students’ Difficulties with Fractions 7 Looking Ahead Connecting the Chapter to Your Practice SECTION I: Understanding Number Talks CHAPTER 1: What Is a Number Talk? Classroom Clip 1.1 16 × 2 : Why Number Talks? 8 Why Number Talks? 9 10 11 13 14 14 xi Understanding Number Talks: Four Foundational Principles Establish a Safe Learning Community 20 Classroom Clip 1.2 4 × 1 : Establishing a Safe Learning Community 22 Use Purposeful Problems 23 Record with Purpose 26 Know When to Ask and When to Tell 28 2 Number Talks and the Standards for Mathematical Practice Classroom Clip 1.3 Placing 0.89 on the Number Line: Number Talks and the Standards for Mathematical Practice Looking Ahead Connecting the Chapter to Your Practice CHAPTER 2: How Do I Get Started with Number Talks? Getting Started: Ten Essentials xii 19 33 36 37 37 38 39 Essential 1: Organize Your Classroom Space to Foster Student Engagement 40 Essential 2: Start with Problems That Give All Students Access and Elicit Thinking from Multiple Perspectives 41 Essential 3: Insist on Students Solving Problems Mentally 41 Essential 4: Provide Appropriate Wait Time 42 Classroom Clip 2.1 Using Hand Signals and Wait Time 42 Essential 5: Accept, Respect, and Consider All Answers 43 Essential 6: Encourage Student Communication Throughout the Number Talk 44 Classroom Clip 2.2 1 1×2 2 5 : Using Turn and Talk with a Number Talk 45 Essential 7: Record Strategies to Make Student Thinking Public 49 Essential 8: Be Prepared When the Sharing of Strategies Doesn’t Go as Anticipated 52 Essential 9: Limit Your Number Talks to Five to Fifteen Minutes 53 Essential 10: Be Patient with Yourself and Your Students 53 Five Ways to Collect Evidence of Students’ Understanding Ask Students to Indicate Which Strategies Are Most Efficient for Them Classroom Clip 2.3 1 7 : Thinking About Efficient Strategies + 2 8 55 55 56 Save Recordings of the Problems Posed and Corresponding Student Strategies 57 Hold Small-Group Number Talks Throughout the Week 57 Create and Post Student-Generated Strategy Charts 58 Give an Occasional Exit Problem at the End of the Number Talk 59 Looking Ahead Connecting the Chapter to Your Practice 59 60 xiii SECTION II: Number Talks to Help Students Build Fractional Reasoning CHAPTER 3: What Are the Big Ideas with Rational Numbers? 63 Big Idea 1: Fractions Are Distinct Numbers 64 Big Idea 2: A Fraction Is Part of a Whole 66 Big Idea 3: The Denominator Is a Divisor and Tells How Many Equal Parts the Whole Is Divided Into 67 Big Idea 4: The Numerator Counts How Many Equal Parts There Are in the Fraction 68 Big Idea 5: There Is an Infinite Number of Fractions Between Any Two Given Fractions 68 Big Idea 6: Equivalence Means That a Fraction Can Be Repartitioned and Renamed in an Infinite Number of Ways 69 Looking Ahead 71 Connecting the Chapter to Your Practice 71 CHAPTER 4: Number Talks to Help Students Build Fractional Reasoning 72 Number Talks That Use Story Problems to Build Fractional Reasoning 73 Classroom Clip 4.1 What is 3 of 12? Using a Story Context 74 Number Talks That Use Area Models to Build Fractional Reasoning 75 4 xiv 61 Category 1: Reasoning About Equal Parts of a Fraction 76 Category 2: Reasoning About Equivalence Among Fractions 82 Classroom Clip 4.2 The Fraction Kit: A Conversation About Equivalence 84 Number Talks That Use Set Models to Build Fractional Reasoning 89 Number Talks That Use Linear Models to Build Fractional Reasoning 93 Category 1: Using Integers as Benchmarks 94 Category 2: Using Integers and Fractions as Benchmarks 96 Number Talks That Use Comparing and Ordering to Build Fractional Reasoning 99 Category 1: Is the Fraction Closer to 0, 21 , or 1 Whole? 100 Category 2: Is the Fraction Closer to 1, 1 21 , or 2 Wholes? 102 Number Talks That Use Strategies for Comparing and Ordering Fractions 104 Category 1: Using Proximity to 21 106 Classroom Clip 4.3 Comparing 24 and 21 107 Category 2: Using Distance from the Whole 108 Category 3: Using Common Numerators 109 Category 4: Using Proportional Reasoning 110 50 40 Looking Ahead Connecting the Chapter to Your Practice CHAPTER 5: Number Talks to Help Students Connect Fractions, Decimals, and Percentages 111 111 113 The Importance of Focusing on Fractions Before Decimals and Percentages 114 Number Talks That Connect Fractions to Percentages 114 Classroom Clip 5.1 : Connecting Fractions to Percentages 1 1 × 4 3 119 xv Category 1: Using Benchmark Fractions to Find Percentages 120 Category 2: Finding Percentages of Whole Numbers 122 Category 3: Comparing and Ordering Fractions and Percentages 124 Number Talks That Connect Fractions to Decimals 125 Classroom Clip 5.2 Placing 0.9, 0.13, 0.255 on the Number Line: Connecting Fractions to Decimals 127 Category 1: Comparing and Ordering Fractions and Decimals 128 Category 2: Comparing Decimals to Decimals 129 Number Talks That Connect Fractions, Decimals, and Percentages 130 Looking Ahead 131 Connecting the Chapter to Your Practice SECTION III: Number Talks to Help Students Operate with Fractions and Decimals CHAPTER 6: Number Talks for Addition with Fractions How Number Talks Help the Development of Addition Strategies with Fractions Making Connections to Strategies for Adding Whole Numbers 132 133 135 136 137 Classroom Clip 6.1 1 5 + : Developing Addition Strategies 2 6 xvi with Fractions 138 Making Connections to the Arithmetic Properties 139 Using Story Problems 141 Using Models 142 Connecting Students’ Strategies 146 Number Talks That Use Area Models for Addition with Fractions 147 Classroom Clip 6.2 Are the Addends Equal to 1? Using Area Models with Addition of Fractions 149 Category 1: Using Area Models Partitioned into Common Denominators 150 Category 2: Using Area Models Requiring Partitioning 153 Number Talks That Use Set Models for Addition with Fractions 157 Category 1: Using Set Models with Eight Dots 159 Category 2: Using Set Models with Twelve Dots 161 Number Talks That Use Linear Models for Addition with Fractions 163 Category 1: Using a Number Line Partitioned into Halves and Fourths 164 Category 2: Using a Number Line Partitioned into Halves and Thirds 166 Number Talks That Highlight the Addition Strategy “Decomposing to Make a Benchmark Number” 168 Classroom Clip 6.3 1 1 1 3 + , + : Developing Addition Strategies 2 2 2 4 with Fractions 169 Category 1: Using Halves as Benchmarks 170 Category 2: Using Wholes as Benchmarks 172 xvii Number Talks That Highlight the Addition Strategy “Adjusting an Addend” 174 Looking Ahead 177 Connecting the Chapter to Your Practice CHAPTER 7: Number Talks for Subtraction with Fractions How Number Talks Help the Development of Subtraction Strategies with Fractions 178 179 180 Making Connections to Strategies for Subtracting Whole Numbers 182 Using Story Problems 183 Using Models 184 Connecting Students’ Strategies 186 Classroom Clip 7.1 3 3 - : Developing Subtraction Strategies 4 8 with Fractions xviii 189 Number Talks That Use Area Models for Subtraction with Fractions 190 Using Area Models Partitioned into Eighths and Twelfths 192 Number Talks That Use Set Models for Subtraction with Fractions 195 Number Talks That Use Linear Models for Subtraction with Fractions 200 Category 1: Using a Number Line Partitioned into Halves and Fourths 201 Category 2: Using a Number Line Partitioned into Halves and Thirds 203 Number Talks That Highlight the Subtraction Strategy “Adding Up” 205 Category 1: Using Like Denominators 207 Category 2: Using Unlike Denominators 209 Number Talks That Highlight the Subtraction Strategy “Removing the Subtrahend in Parts” 211 Number Talks That Highlight the Subtraction Strategy “Partial Differences” 214 Looking Ahead 217 Connecting the Chapter to Your Practice CHAPTER 8: Number Talks for Multiplication with Fractions How Number Talks Help the Development of Multiplication Strategies with Fractions 218 219 220 Making Connections to Strategies for Multiplying Whole Numbers 221 Making Connections to Arithmetic Properties 224 Highlighting the Shifting Whole 225 Classroom Clip 8.1 1 1 × : Developing Multiplication Strategies 4 3 with Fractions 227 Using Story Problems 227 Using Models 229 Classroom Clip 8.2 of 12, 41 of 12: Developing Multiplication Strategies with Fractions 231 1 2 Connecting Students’ Strategies 232 Number Talks That Use Unit Fractions and Whole Numbers with Multiplication 236 Number Talks That Use Fractions and Whole Numbers with Multiplication 238 xix Number Talks That Use Models to Focus on the Shifting Whole 242 Number Talks That Use Unit Fractions with Multiplication 244 Number Talks That Highlight the Multiplication Strategy “Partial Products” Classroom Clip 8.3 1 31 × 43 : Developing Multiplication Strategies with Fractions 247 Category 1: Multiplying a Fraction by a Whole Number 248 Category 2: Multiplying a Mixed Number by a Fraction 250 Category 3: Multiplying a Fraction by a Fraction 252 Number Talks That Highlight the Multiplication Strategy “Switching Numerators or Denominators” 254 Number Talks That Highlight the Multiplication Strategy “Decomposing Factors into Factors” 258 Category 1: Multiplying a Fraction by a Whole Number 259 Category 2: Multiplying a Fraction by a Fraction 261 Number Talks That Highlight the Multiplication Strategy “Doubling and Halving” Classroom Clip 8.4 Doubling and Halving to Solve 1 2 × 4 3 263 265 Category 1: Multiplying Whole Numbers and Fractions 266 Category 2: Multiplying a Fraction by a Fraction 268 Looking Ahead xx 246 Connecting the Chapter to Your Practice 270 271 CHAPTER 9: Number Talks for Division with Fractions How Number Talks Help the Development of Division Strategies with Fractions 273 274 Making Connections to Strategies for Dividing Whole Numbers 275 Highlighting the Shifting Whole 278 Classroom Clip 9.1 1 ÷ 3 : Developing Division Strategies with Fractions 281 8 Using Story Problems 282 Using Models 284 Connecting Students’ Strategies 287 Number Talks That Use Whole Numbers and Unit Fractions with Division 290 Category 1: Using Whole Number Divisors with Mixed Number Quotients 291 Category 2: Using Whole Number Divisors with Quotients Less Than 1 293 Category 3: Using a Unit Fraction as the Divisor 295 Number Talks That Highlight the Division Strategy “Proportional Reasoning” 297 Classroom Clip 9.2 6 ÷ 3, 3 ÷ 1 1 , 1 1 ÷ 3 : Proportional 2 2 Reasoning String 4 Number Talks That Highlight the Division Strategy “Common Denominators” 299 302 Category 1: Using the Same Divisors 303 Category 2: Using Equivalent Divisors 305 Number Talks That Highlight the Division Strategy “Partial Quotients” 307 xxi Number Talks That Highlight the Division Strategy “Multiplying Up” 310 Looking Ahead 314 Connecting the Chapter to Your Practice 315 CHAPTER 10: Number Talks for Operating with Decimals 316 How Number Talks Help the Development of Computation Strategies with Decimals 318 Making Connections to Strategies for Computing with Whole Numbers 319 Making Connections to Arithmetic Properties 323 Using Story Problems 324 Using Models 325 Connecting Students’ Strategies 330 Section 1: Number Talks for Addition with Decimals333 Number Talks That Highlight a Place to Begin with Addition of Decimals 333 Number Talks That Highlight the Addition Strategy “Adding by Place Value” 336 Category 1: Adding Tenths and Hundredths 337 Category 2: Adding Hundredths and Thousandths339 Number Talks That Highlight the Addition Strategy “Adding Up by Chunks” Category 1: Adding Hundredths 341 342 Category 2: Adding Hundredths and Thousandths344 xxii Number Talks That Highlight the Addition Strategy “Making Benchmark Numbers” 346 Category 1: Adding Hundredths 347 Category 2: Adding Mixed Decimals 348 Section 2: Number Talks for Subtraction with Decimals 349 Number Talks That Highlight the Subtraction Strategy “Adding Up” 349 Category 1: Subtracting Hundredths 351 Category 2: Subtracting Multiple Place Values 353 Number Talks That Highlight the Subtraction Strategy “Adjusting the Minuend or Subtrahend” 354 Category 1: Adjusting the Subtrahend 356 Category 2: Adjusting the Minuend 357 Number Talks That Highlight the Subtraction Strategy “Constant Difference” 358 Category 1: Subtracting Hundredths 359 Category 2: Subtracting Mixed Decimals 361 Number Talks That Highlight the Subtraction Strategy “Subtracting by Place Value” 362 Category 1: Using Place Values 364 Category 2: Using Negative Numbers 366 Section 3: Number Talks for Multiplication with Decimals 368 Number Talks That Highlight a Place to Begin with Multiplication of Decimals 368 Category 1: Ten Times Smaller 369 Category 2: Ten Times Larger 371 xxiii Number Talks That Highlight the Multiplication Strategy “Partial Products” 373 Category 1: Using Whole Numbers and Decimals 375 Category 2: Using Mixed Decimals 377 Number Talks That Highlight the Multiplication Strategy “Breaking Factors into Factors” 379 Category 1: Using Tenths as a Multiplier 380 Category 2: Using Hundredths as a Multiplier 382 Number Talks That Highlight the Multiplication Strategy “Doubling and Halving” Using Number Talk Strings 384 385 Section 4: Number Talks for Division with Decimals 387 Number Talks That Highlight the Division Strategy “Proportional Reasoning” 387 Category 1: Using Whole Numbers and Decimals 389 Category 2: Using Decimals 391 Number Talks That Highlight the Division Strategy “Multiplying Up” 393 Number Talks That Highlight the Division Strategy “Partial Quotients” 396 Looking Ahead 398 Connecting the Chapter to Your Practice 398 References399 To purchase the reproducible versions of the area, set, and linear models in this resource, visit www.mathsolutions.com/ numbertalksfdp_reproducibles. xxiv