EACH CHAPT ER INCLUDES: • Prescriptive targeted strategic intervention charts. • Student activity pages aligned to the Common Core State Standards. • Complete lesson plan pages with lesson objectives, getting started activities, teaching suggestions, and questions to check student understanding. Grade 4 Targeted Strategic Intervention Grade 4, Chapter 5 Based on student performance on Am I Ready?, Check My Progress, and Review, use these charts to select the strategic intervention lessons found in this packet to provide remediation. Am I Ready? Where is this concept in My Math? If Students miss Exercises… Then use this Strategic Intervention Activity… Concept 1-3 5-A: Round to the Nearest Ten or Hundred Round 4.NBT.3 Chapter 1, Lesson 5 4-6 5-B: Add Two-Digit Numbers Addition 4.NBT.4 Chapter 2, Lesson 3 7-8 5-C: Repeated Addition Model multiplication 4.NBT.5 Chapter 4, Lesson 4 9-10 5-D: Multiplication Facts Through 9 Multiplication 4.NBT.5 Chapter 4, Lesson 3 Check My Progress 1 Where is this concept in My Math? If Students miss Exercises… Then use this Strategic Intervention Activity… Concept 4-6 5-E: Multiples of 10 Multiply by tens 4.NBT.5 5-F: Estimate Products Estimate products 4.NBT.3 7-9 Chapter 5, Lesson 1 Chapter 5, Lesson 2 Review Where is this concept in My Math? If Students miss Exercises… Then use this Strategic Intervention Activity… Concept 6-9 5-G: Multiplication Facts Multiply by tens 4.NBT.5 Chapter 5, Lesson 1 5-I: Compare Numbers with Two- and Three -Digits Estimate products 4.NBT.3 Chapter 5, Lesson 2 5-J: Multiplication with Regrouping Multiply two, twodigit numbers 4.NBT.5 Chapter 5, Lesson 4 5-H: Round to the Nearest Ten 10-13 14-17 Name Round to the Nearest Ten or Hundred Lesson 5-A You can round numbers by using place value. thousands 3 What Can I Do? I want to round to the nearest ten or hundred. hundreds tens ones 3 6 1 Round 3,361 to the nearest hundred. • Find the hundreds place. • Look at the digit to its right. 3,361 If the digit is 5 or greater, round up. If the digit is less than 5, round down. Since 6 > 5, round up. To the nearest hundred, 3,361 rounds up to 3,400. Round 3,361 to the nearest ten. • Find the tens place. • Look at the digit to its right. 3,361 Copyright © The McGraw-Hill Companies, Inc. If the digit is 5 or greater, round up. If the digit is less than 5, round down. Since 1 < 5, round down. To the nearest ten, 3,361 rounds down to 3,360. Round each number to the nearest ten. 1. 35 2. 83 3. 671 4. 982 5. 1,309 6. 3,357 Round each number to the nearest hundred. 7. 293 8. 646 9. 485 10. 8,128 11. 4,151 12. 1,207 Name Round each number to the underlined place. 13. 4,147 14. 281 15. 867 16. 54 17. 3,163 18. 5,247 19. 8,724 20. 3,955 21. 7,299 22. 2,709 23. 4,277 24. 5,529 Lesson 5-A Round to the nearest ten. 25. 3,849 26. 4,323 27. 9,322 28. 8,234 29. 483 30. 5,801 31. 3,735 32. 969 33. 365 34. 492 35. 3,655 36. 9,118 37. 779 38. 789 39. 2,615 40. 583 41. 1,488 42. 883 43. 3,814 44. 698 45. 8,712 46. 6,479 47. 5,656 48. 3,344 Copyright © The McGraw-Hill Companies, Inc. Round to the nearest hundred. USING LESSON 5-A Name Round to the Nearest Ten or Hundred Lesson Goal thousands I want to round to the nearest ten or hundred. • Identify the tens place. • Identify the hundreds place. • Identify multiples of 10 and 100. • Repeat the activity by marking 15 on the number line. Students should find that 15 appears exactly halfway between two tens. Tell students that if a number is halfway between two tens, it is rounded to the greater ten. 6 1 Round 3,361 to the nearest hundred. • Find the hundreds place. • Look at the digit to its right. 3,361 Round 3,361 to the nearest ten. • Find the tens place. • Look at the digit to its right. 3,361 Copyright © The McGraw-Hill Companies, Inc. If the digit is 5 or greater, round up. If the digit is less than 5, round down. Since 1 < 5, round down. To the nearest ten, 3,361 rounds down to 3,360. Round each number to the nearest ten. 1. 35 40 2. 83 4. 982 980 5. 1,309 80 1,310 3. 671 6. 3,357 670 3,360 Round each number to the nearest hundred. 7. 293 10. 8,128 300 8,100 8. 646 11. 4,151 600 4,200 9. 485 12. 1,207 500 1,200 141_142_S_G4_C05_SI_119816.indd 141 7/9/12 1:31 PM WHAT IF THE STUDENT NEEDS HELP TO Identify the Tens Place 10 11 12 13 14 15 16 17 18 19 20 3 If the digit is 5 or greater, round up. If the digit is less than 5, round down. Since 6 > 5, round up. To the nearest hundred, 3,361 rounds up to 3,400. Getting Started Read the question and the response. Then read and discuss the examples. • Ask students to mark 11 and 18 on a number line and draw an arrow connecting each number with the number they round to. Point out that each number is closer to the multiple of ten that it rounds to on the number line. hundreds tens ones 3 What Can I Do? What the Student Needs to Know What Can I Do? 5-A You can round numbers by using place value. • Round to the nearest ten or hundred. • Write 40, 50, and 60 on the board. Remind students that these are called multiples of 10. • Ask: What are the two multiples of 10 nearest to 43? (40 and 50) To 57? (50 and 60) • Write 400, 500, and 600 on the board. Remind students that these are called multiples of 100. • Ask: What are the two multiples of 100 nearest to 438? (400 and 500) To 572? (500 and 600) Lesson • Use place-value charts for two-, three-, and four-digit numbers. • Use base-ten blocks to review the meaning of the digits in two- and three-digit numbers. Identify the Hundreds Place • Use place-value charts and base-ten blocks to model three- and four-digit numbers. • Use color-coded cards. Give each pair of students 3 crayons (red, yellow, and blue) and 3 index cards. Students should write a number from 1 to 9 on each card, using a different color for each. Create three-digit place-value charts. Have the students shade the columns: ones, red; tens, yellow; hundreds, blue. Have pairs match each number card by its color to a column on the chart. Identify Multiples of 10 and 100 • Count aloud by 10s from 10 to 100. Have the student write these multiples of 10 on the board. Point out that a multiple of 10 has a zero in the ones place. Repeat the activity with multiples of 100. Name Lesson Round each number to the underlined place. 13. 4,147 16. 54 4,150 50 14. 281 300 15. 867 5-A • Have students write 3,361 in a place-value chart and round it to the nearest ten, explaining the rule used. (3,360; If the ones digit is less than 5, round down.) • Ask students to round 3,361 to the nearest hundred. Explain that instead of using the ones digit, they will use the tens digit and the same rules for rounding. Have students identify the digit in the tens place and determine whether to round to the next greater hundred. (6 tens; Round 3,361 up to 3,400.) 870 17. 3,163 3,200 18. 5,247 5,250 19. 8,724 8,700 20. 3,955 4,000 21. 7,299 7,300 22. 2,709 2,710 23. 4,277 4,300 24. 5,529 5,500 Round to the nearest ten. 25. 3,849 3,850 26. 4,323 4,320 27. 9,322 9,320 28. 8,234 8,230 29. 483 480 30. 5,801 5,800 31. 3,735 3,740 32. 969 34. 492 490 35. 3,655 970 3,660 33. 365 36. 9,118 370 Try It 9,120 • Work through Exercises 1 and 2 with students. Have students use the ones digit to round to the nearest ten. Have students demonstrate or explain how they found their answers to each exercise. For Exercises 3–6, have students tell you the tens digit in each number. For Exercises 7–12, have them tell you the hundreds digit. 37. 779 800 38. 789 40. 583 600 41. 1,488 43. 3,814 3,800 44. 698 46. 6,479 6,500 47. 5,656 800 1,500 700 5,700 39. 2,615 42. 883 2,600 900 45. 8,712 8,700 48. 3,344 3,300 Copyright © The McGraw-Hill Companies, Inc. Round to the nearest hundred. Power Practice 141_142_S_G4_C05_SI_119816.indd 142 7/9/12 1:32 PM WHAT IF THE STUDENT NEEDS HELP TO Complete the Power Practice • Have the student draw number lines to show the exercises. When rounding to the nearest ten, the number line is numbered by 1s. When rounding to the nearest hundred, the number line is numbered by 10s. • Have the student underline the number in the place they are rounding to, then circle the digit to the right. • The student may have difficulty finding the halfway point on a number line. Distribute number lines marked 0–100, 100–200, 300–400, and so on up to 900–1,000. Have the student point and follow on their number lines as you model how he or she can count forward to find the middle or halfway point. Mark each halfway point with a symbol such as a stop sign. Repeat with different marked number lines until the student recognizes the pattern that the halfway point always includes the number 50. • Before doing the exercises, check that students fully grasp the importance of ones when rounding to the nearest ten. The digit in the ones place determines how the digit in the tens place is rounded. • Have the students read the directions and look over the practice items. Lesson 5-A Name Add Two-Digit Numbers What Can I Do? Lesson 5-B Decide whether to regroup. 26 + 47 26 + 43 I want to add two-digit numbers. Think: I can add 6 ones and 3 ones without regrouping. I can’t add 6 ones and 7 ones without regrouping. No Regrouping Regroup 13 ones as 1 ten 3 ones. 1 26 + 47 73 26 + 43 69 Add the other way to check. Copyright © The McGraw-Hill Companies, Inc. Check addition by adding in the other direction. 26 + 43 69 43 + 26 69 26 + 47 73 1 47 + 26 73 Circle Regroup or No Regrouping. Then add. 1. 55 + 34 Regroup No Regrouping 2. 62 + 19 Regroup No Regrouping Name Lesson Circle Regroup or No Regrouping. Then add. 3. 28 + 17 Regroup 5-B 4. 31 + 27 No Regrouping 5. 24 + 48 Regroup No Regrouping 6. Regroup No Regrouping 16 + 27 Regroup No Regrouping 7. 32 + 8 8. 40 + 22 9. 57 + 27 10. 33 + 29 11. 64 + 31 12. 65 + 6 13. 42 + 52 14. 35 + 45 15. 86 + 12 16. 14 + 68 17. 21 + 67 18. 47 + 39 19. 13 + 18 20. 53 + 8 21. 46 + 19 Copyright © The McGraw-Hill Companies, Inc. Add. Check by adding in the other direction. USING LESSON 5-B Name Add Two-Digit Numbers Lesson 5-B Lesson Goal • Add two-digit numbers, with and without regrouping. What Can I Do? Decide whether to regroup. What the Student Needs to Know • Regroup ones as tens and ones. • Check addition. Think: I can add 6 ones and 3 ones without regrouping. I can’t add 6 ones and 7 ones without regrouping. No Regrouping Regroup 13 ones as 1 ten 3 ones. Getting Started Add the other way to check. Check addition by adding in the other direction. 26 + 43 69 43 + 26 69 26 + 47 73 1 47 + 26 73 Circle Regroup or No Regrouping. Then add. 1. What Can I Do? Read the question and the response. Then read and discuss the examples. Ask: • Why can you add 6 ones and 3 ones without regrouping? (They add up to 9 ones, which is less than the 10 ones needed for regrouping.) • Why do you need to regroup when you add 6 ones and 7 ones? (They add up to 13 ones, which is more than 10 ones or 1 ten.) 1 26 + 47 73 26 + 43 69 Copyright © The McGraw-Hill Companies, Inc. Use tens and ones base-ten blocks to show the numbers 13 and 18. Ask: • How many tens are in each number? How many ones are in each number? (1 ten, 3 ones; 1 ten, 8 ones) Put the blocks together. Say: • I’m adding 13 and 18. Now how many tens do I have? How many ones do I have? (2 tens, 11 ones) • What can I do with 11 ones? (Regroup as 1 ten and 1 one.) • Now how many tens do I have? How many ones do I have? (3 tens, 1 one) 26 + 47 26 + 43 I want to add two-digit numbers. 55 + 34 89 Regroup No Regrouping 2. 62 + 19 81 Regroup No Regrouping 145_146_S_G4_C05_SI_119816.indd 145 7/9/12 2:31 PM WHAT IF THE STUDENT NEEDS HELP TO Regroup Ones as Tens and Ones • Give the student 18 ones base-ten blocks and 5 tens blocks. Have the student show addends like these: 32 + 18; 17 + 25; 29 + 17. After showing the addends, have the student put the base-ten blocks together and regroup any groups of 10 ones for 1 ten before finding the sum. Encourage the student to talk about each step of the process. Check Addition • Display addition fact cards to 18 and have the student use counters to model the facts. • Then ask the student to check the addition by adding the numbers in a different direction and using counters to model the new fact. Name Lesson Circle Regroup or No Regrouping. Then add. 3. 5. 28 + 17 45 Regroup 24 + 48 72 Regroup 5-B 4. No Regrouping 6. No Regrouping 31 + 27 58 Regroup 16 + 27 43 Regroup Try It • Remind students that they only need to look at the ones digits to know whether or not to regroup. If the ones add up to less than 10, no regrouping is needed. If they add up to 10 or more, you must regroup. • Make sure students realize that they are to add as well as to circle the correct choice. No Regrouping No Regrouping Add. Check by adding in the other direction. 8. 10. 33 + 29 62 13. 40 + 22 62 9. 57 + 27 84 11. 64 + 31 95 12. 65 + 6 71 42 + 52 94 14. 35 + 45 80 15. 86 + 12 98 16. 14 + 68 82 17. 21 + 67 88 18. 47 + 39 86 19. 13 + 18 31 20. 53 + 8 61 21. 46 + 19 65 Power Practice • If necessary, provide additional paper for students to check their answers. • Have students complete the practice items. Then review each answer. Copyright © The McGraw-Hill Companies, Inc. 32 + 8 40 7. 145_146_S_G4_C05_SI_119816.indd 146 7/9/12 2:32 PM WHAT IF THE STUDENT NEEDS HELP TO Complete the Power Practice • Discuss each incorrect answer. Have the student tell which addition problems require regrouping and which do not. • Watch for students who consistently forget to add the regrouped ten. Remind them to write the 1 above the tens after they add the ones. Lesson 5-B Name Repeated Addition Lesson 5-C Use skip counting. What Can I Do? I want to add the same number more than one time. Find 4 + 4 + 4 + 4 + 4. Look at the number of 4s. There are five 4s. Skip count by 4s five times. 4 + 4 + 4 + 4 + 4 4, 8, 12, 16, 20 So, 4 + 4 + 4 + 4 + 4 = 20 Find each sum. Skip count to help. 1. 2 + 2 + 2 + 2 = 2. 5 + 5 + 5 = Skip count by 2s Copyright © The McGraw-Hill Companies, Inc. , , Skip count by 5s. , , , Find each sum. 3. 3 + 3 + 3 + 3 + 3 = 4. 6 + 6 + 6 = 5. 4 + 4 + 4 + 4 = 6. 5 + 5 + 5 + 5 + 5 + 5 = 7. 7 + 7 + 7 + 7 = 8. 8 + 8 + 8 + 8 = 9. 2 + 2 + 2 + 2 + 2 + 2 = 10. 9 + 9 + 9 + 9 + 9 + 9 = USING LESSON 5-C Name Repeated Addition Lesson 5-C Lesson Goal Use skip counting. • Use skip counting to add the same number three or more times. What Can I Do? Find 4 + 4 + 4 + 4 + 4. I want to add the same number more than one time. What the Student Needs to Know Look at the number of 4s. There are five 4s. Skip count by 4s five times. 4 + 4 + 4 + 4 + 4 • Use skip counting. 4, Getting Started Ask students to look at this example: 2 + 2 + 2. Say: • When you add these numbers, you skip the numbers between them. • The numbers you count are ? . (2, 4, 6) • The numbers you skip are ? . (3, 5) Read the question and the response. Then look at the example. Ask: • How many 4s are being added? (5) • How many times do you skip count 4? (5) Skip count with students: 4, 8, 12, 16, 20. You may want to have students count the in-between numbers with a ruler: Say: 4; Use your finger to point to 5, 6, and 7 on the ruler. Try It • Have students read Exercise 1 and count the number of 2s. Have students write the correct numbers on the lines by skip counting. • Have students follow the same procedure for Exercise 2. Power Practice • Have students complete the practice items. Then review each answer. 12, 16, 20 Find each sum. Skip count to help. 8 1. 2 + 2 + 2 + 2 = 2. 5 + 5 + 5 = 15 Skip count by 2s 2 Copyright © The McGraw-Hill Companies, Inc. What Can I Do? 8, So, 4 + 4 + 4 + 4 + 4 = 20 , 4 , Skip count by 5s. 6 , 8 5 , 10 , 15 Find each sum. 3. 3 + 3 + 3 + 3 + 3 = 15 4. 6 + 6 + 6 = 18 5. 4 + 4 + 4 + 4 = 16 6. 5 + 5 + 5 + 5 + 5 + 5 = 30 7. 7 + 7 + 7 + 7 = 28 8. 8 + 8 + 8 + 8 = 32 9. 2 + 2 + 2 + 2 + 2 + 2 = 12 10. 9 + 9 + 9 + 9 + 9 + 9 = 54 149_S_G4_C05_SI_119816.indd 149 7/9/12 2:36 PM WHAT IF THE STUDENT NEEDS HELP TO Use Skip Counting • Use counters to form groups for skip counting. Show the student that by gathering the counters into groups of, say, 4, they can count 1-2-3-4, then 5-6-7-8, and so on. The last number in each group of 4 becomes the next number in the skip counting pattern. • Practice selected addition facts daily for 5 or 10 minutes: adding equal numbers, such as 4 + 4, then 4 to the sum of that (8 + 4), and so on. Repeat until the student can recall the sums for these addition facts automatically. Complete the Power Practice • Discuss each incorrect answer. • Perhaps the student will understand the concept of skip counting if presented in a different modality; for example, draw picture models (shade every fourth frog he or she draws) or playing a game (every fourth student stands up). Name Multiplication Facts Through 9 Lesson 5-D Use any multiplication strategy. What Can I Do? I want to multiply two numbers. Find 6 × 5. Double a known fact. Use repeated addition. Double 3 × 5 to find 6 × 5. Add 5 six times. 3 × 5 = 15 15 + 15 = 30 5 + 5 + 5 + 5 + 5 + 5 = 30 So, 6 × 5 = 30. So, 6 × 5 = 30. Skip count on a number line. Skip count by 5s six times. 0 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 Copyright © The McGraw-Hill Companies, Inc. So, 6 × 5 = 30. Double a known fact to find each product. 1. 4 × 9 = Double 2 × 9 3. 6 × 5 = Double 3 × 5. 2. 8 × 5 = Double 4 × 5 4. 10 × 7 = Double 5 × 7 Name Lesson Use repeated addition to find each product. 5. 3 × 7 = 5-D 6. 5 × 5 = Add: Skip count to find each product. 8. 4 × 6 = 7. 5 × 3 = Count: Count: 9. 2 × 6 = 10. 4 × 4 = 11. 5 × 7 = 12. 6 × 7 = 13. 3 × 8 = 14. 9 × 3 = 15. 7 × 4 = 16. 8 × 6 = 17. 5 × 8 = 18. 8 ×2 19. 3 ×6 20. 7 ×7 21. 9 ×3 22. 6 ×6 23. 9 ×8 24. 8 ×4 25. 6 ×9 26. 9 ×4 27. 7 ×8 28. 7 ×9 29. 9 ×9 Copyright © The McGraw-Hill Companies, Inc. Find each product. Use any method. USING LESSON 5-D Name Multiplication Facts Through 9 Lesson Goal 5-D Use any multiplication strategy. • Use any multiplication strategy to multiply two numbers through 9. What Can I Do? I want to multiply two numbers. What the Student Needs to Know • Double a basic multiplication fact. • Use repeated addition. • Skip count. Find 6 × 5. Double a known fact. Use repeated addition. Double 3 × 5 to find 6 × 5. Add 5 six times. 3 × 5 = 15 15 + 15 = 30 5 + 5 + 5 + 5 + 5 + 5 = 30 So, 6 × 5 = 30. So, 6 × 5 = 30. Skip count on a number line. Getting Started Skip count by 5s six times. 0 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 So, 6 × 5 = 30. Copyright © The McGraw-Hill Companies, Inc. • Write the multiplication fact 3 × 7 on the board. Say: • Of the three strategies of doubling a known fact, repeated addition, and skip counting on a number line, which ones can be used for this example? (repeated addition, skip counting on a number line) • Explain that it is necessary to have one of the factors be an even number to be able to use the doubling method, because you don’t get a whole number when you divide an odd number by 2. Lesson Double a known fact to find each product. 1. 4 × 9 = 36 Double 2 × 9 3. 6 × 5 = 30 Double 3 × 5. 2. 8 × 5 = 40 Double 4 × 5 4. 10 × 7 = 70 Double 5 × 7 What Can I Do? Read the question and the response. Then discuss the first example. Ask: • Can you use the doubling method to find the answer to the example 6 × 5? (Yes) • What would you double? (3 × 5 = 15) • How would you use repeated addition to solve? (add 5 six times: 5 + 5 + 5 + 5 + 5 + 5) Use an existing number line from 1 to 30 or draw a new one. Demonstrate skip counting 6 groups of 5 by drawing arrows that show “jumps” between 0 and 5, 5 and 10, 10 and 15, 15 and 20, 20 and 25, and 25 and 30. • Ask: Which two methods are most alike? (repeated addition and skip counting) 151_152_S_G4_C05_SI_119816.indd 151 7/9/12 2:41 PM WHAT IF THE STUDENT NEEDS HELP TO Double a Basic Multiplication Fact • Have the student keep handy a chart of numbers and their doubles (2 × 2 = 4, 3 × 3 = 9, and so on) to refer to. • Have the student practice these doubling facts daily until he or she knows them. Use Repeated Addition • Practice selected addition facts daily for 5 or 10 minutes: adding equal numbers, such as 4 + 4, then 4 to the sum of that (8 + 4), and so on. Repeat until the student can recall the sums for these addition facts automatically. • If this is still difficult, have the student use counters to form groups for repeated addition. Name Lesson Use repeated addition to find each product. 5. 3 × 7 = 21 5-D Try It 6. 5 × 5 = 25 • Have students do Exercises 1–4 using the doubling method. Check that students understand that they must use the even number as their “double.” Ask what would happen if both numbers were even. (They would have a choice of which factor to use as the double.) • Have students do Exercises 5 and 6 using repeated addition. Check to make sure students are clear on which is the number to add and which tells the number of times it gets added. • Have students do Exercises 7 and 8 by skip counting. Check to make sure students are clear on which is the number to skip count and which tells the number of times it gets counted. Add: 5 + 5 + 5 + 5 + 5 = 25 Add: 7 + 7 + 7 = 21 Skip count to find each product. 7. 5 × 3 = 15 8. 4 × 6 = 24 Count: 3, 6, 9, 12, 15 Count: 6, 12, 18, 24 Find each product. Use any method. 9. 2 × 6 = 12 10. 4 × 4 = 16 11. 5 × 7 = 35 12. 6 × 7 = 42 13. 3 × 8 = 24 14. 9 × 3 = 27 15. 7 × 4 = 28 16. 8 × 6 = 48 40 18. 8 ×2 16 19. 3 ×6 18 20. 7 ×7 49 21. 9 ×3 27 22. 6 ×6 36 23. 9 ×8 72 24. 8 ×4 32 25. 6 ×9 54 9 ×4 36 27. 7 ×8 56 28. 7 ×9 63 29. 26. 9 ×9 81 Copyright © The McGraw-Hill Companies, Inc. 17. 5 × 8 = 151_152_S_G4_C05_SI_119816.indd 152 Power Practice • Have students complete the practice items. Then review each answer. 7/9/12 2:42 PM WHAT IF THE STUDENT NEEDS HELP TO Skip Count • Show the student that by gathering counters into groups of, say, 4, he or she can count 1-2-3-4, then 5-6-7-8, and so on. The last number in each group of 4 becomes the next number in skip counting. Complete the Power Practice • Discuss each incorrect answer and review the previous skills, if necessary. Lesson 5-D Name Multiples of 10 Lesson 5-E Find 4 × 20. Use a basic fact. What Can I Do? I want to use basic facts and patterns to find a multiple of 10. Use multiples of 10. 20 is a multiple of 10 because 2 × 10 = 20 Think: 4 × 2 = 8 Think: 4 × 2 = 8 Apply the pattern: 4 × 20 = 80 Use basic facts to multiply. 1. 2 × 30 = 2. 2 × 70 = 3. 3 × 50 = 4. 3 × 40 = 5. 8 × 10= 6. 4 × 50 = 7. 5 × 70 = 8. 6 × 30 = Copyright © The McGraw-Hill Companies, Inc. Multiply. 9. 30 × 7 10. 50 × 5 11. 40 × 8 12. 30 × 9 13. 90 × 5 14. 60 × 6 15. 90 × 4 16. 80 × 3 17. 2 × 60 = 18. 3 × 70 = 19. 5 × 40 = 20. 9 × 20 = 21. 6 × 80 = 22. 4 × 70 = USING LESSON 5-E Name Multiples of 10 Lesson 5-E Lesson Goal • Use basic facts and patterns to find multiples of 10. I want to use basic facts and patterns to find a multiple of 10. What the Student Needs to Know 20 is a multiple of 10 because 2 × 10 = 20 Think: 4 × 2 = 8 Apply the pattern: 4 × 20 = 80 Use basic facts to multiply. Getting Started • Conduct a brief review of the multiplication facts, emphasizing the more difficult facts. If necessary, post a multiplication facts table for student reference. 1. 2 × 30 = 60 2. 2 × 70 = 140 3. 3 × 50 = 150 4. 3 × 40 = 120 5. 8 × 10= 80 6. 4 × 50 = 200 7. 5 × 70 = 350 8. 6 × 30 = 180 Multiply. Copyright © The McGraw-Hill Companies, Inc. Read the question and the response. Then read and discuss the examples. Ask: • What multiplication fact is “hidden” in 4 × 30? (4 × 3 = 12) • How does knowing the product of 4 × 3 help you solve 4 × 30? (Possible answer: I can multiply 4 × 3 and then add a zero at the end.) Use multiples of 10. Think: 4 × 2 = 8 • Identify ones and tens digits. • Complete multiplication facts. • Recognize multiples of 10. What Can I Do? Find 4 × 20. Use a basic fact. What Can I Do? 9. 30 × 7 210 10. 50 × 5 250 11. 40 × 8 320 12. 30 × 9 270 13. 90 × 5 450 14. 60 × 6 360 15. 90 × 4 360 16. 80 × 3 240 17. 2 × 60 = 120 18. 3 × 70 = 210 19. 5 × 40 = 200 20. 9 × 20 = 180 21. 6 × 80 = 480 22. 4 × 70 = 280 Try It • Have students tell you the basic fact that corresponds with each exercise. 155_S_G4_C05_SI_119816.indd 155 7/9/12 2:45 PM WHAT IF THE STUDENT NEEDS HELP TO Power Practice • Have students state the basic fact that corresponds with each exercise. • Select a few of the exercises and have volunteers demonstrate how they solved it. Identify Ones and Tens Digits • Write a two-digit number such as 83 on the board. Ask: How many tens are in this number? How many ones? (8 tens, 3 ones) Remind the student that the 8 is called the tens digit. It tells the number of tens. The 3 is the ones digit because it tells the number of ones. Complete Multiplication Facts • Have the student work in pairs using flash cards to identify any unknown facts. He or she can use counters or base-ten blocks to demonstrate the products of multiplying 2 one-digit numbers. Recognize Multiples of 10 • Remind the student that any number ending in zero is a multiple of 10. Name Estimate Products What Can I Do? I want to estimate the answer to a multiplication problem. Lesson 5-F Round the greater factor. Multiply to estimate. Round the greater number so that it has only one digit that is not zero. 6 × 3 = 18 60 × 3 = 180 So, 62 × 3 is about 180. 62 × 3 → 60 × 3 8 × 27 → 8 × 30 8 × 3 = 24 8 × 30 = 240 So, 8 × 27 is about 240. 8 × 6 = 48 80 × 6 = 480 So, 78 × 6 is about 480. 78 × 6 → 80 × 6 Copyright © The McGraw-Hill Companies, Inc. Round the factor to the underlined digit. 1. 7 × 57 → 7 × 2. 2 × 32 → 2 × 3. 9 × 94 → 9 × 4. 8 × 25 → 8 × 5. 5 × 44 → 5 × 6. 3 × 74 → 3 × Round the factor to the underlined digit to estimate the product. 7. 3 × 67 → 3 × estimate: 9. 4 × 21 → 4 × 8. 9 × 18 → 9 × estimate: 10. 7 × 89 → 7 × estimate: estimate: 11. 6 × 78 → 6 × 12. 5 × 35 → 5 × estimate: estimate: USING LESSON 5-F Name Estimate Products Lesson 5-F Lesson Goal • Use rounding to estimate the product of a one-digit number by a two-digit number. What Can I Do? I want to estimate the answer to a multiplication problem. What the Student Needs to Know Round the greater factor. Multiply to estimate. Round the greater number so that it has only one digit that is not zero. 6 × 3 = 18 60 × 3 = 180 So, 62 × 3 is about 180. 62 × 3 → 60 × 3 • Round to the nearest ten. • Complete multiplication facts. 8 × 27 → 8 × 30 Getting Started 78 × 6 → 80 × 6 What Can I Do? Read the question and the response. Then have students study the three examples. • How have the three problems been changed? (The greater number has been rounded.) • Have students read the sentences on the right to learn how to estimate. Try It • Have students identify the underlined digit in the first exercise. Ask: How will you round the number 57? (Look at the digit to the right of the underlined digit. It is greater than 5, so 57 rounds up 60.) Power Practice • Have students complete the practice items. Then review each answer. 8 × 6 = 48 80 × 6 = 480 So, 78 × 6 is about 480. Round the factor to the underlined digit. Copyright © The McGraw-Hill Companies, Inc. • Write 50, 60, and 70 on the board. Remind students that these are called multiples of 10. • What are the two multiples of 10 nearest to 53? (50 and 60) To 67? (60 and 70) • Have students find the tens place and identify the digit to its right. (ones place) • If the digit is 5 or greater, round up. If the digit is less than 5, round down. 8 × 3 = 24 8 × 30 = 240 So, 8 × 27 is about 240. 1. 7 × 57 → 7 × 60 2. 2 × 32 → 2 × 30 3. 9 × 94 → 9 × 90 4. 8 × 25 → 8 × 30 5. 5 × 44 → 5 × 40 6. 3 × 74 → 3 × 70 Round the factor to the underlined digit to estimate the product. 7. 3 × 67 → 3 × 70 8. 9 × 18 → 9 × 20 estimate: 210 estimate: 180 9. 4 × 21 → 4 × 20 10. 7 × 89 → 7 × 90 estimate: 80 estimate: 630 11. 6 × 78 → 6 × 80 12. 5 × 35 → 5 × 40 estimate: 480 estimate: 200 157_S_G4_C05_SI_119816.indd 157 7/9/12 2:53 PM WHAT IF THE STUDENT NEEDS HELP TO Round to the Nearest Ten • Draw number lines using two-digit numbers. Remind the student of the rules for rounding: If the ones digit is equal to or greater than 5, round up. If the ones digit is less than 5, round down. Complete Multiplication Facts • Have the student work in pairs using flash cards to identify those facts they do not know. Then have students form small groups to create and share fact strategies for the unknown facts. Complete the Power Practice • If the student is not rounding correctly, have him or her identify two nearest multiples first. For example, the two tens closest to 21 are 20 and 30. Name Multiplication Facts Lesson 5-G Use an array. Draw a picture or use counters. What Can I Do? I want to find the product of two numbers. 6×7 6, the first factor, tells the number of rows. 7, the second factor, tells the number in each row. Count to find the product. 6 × 7= 42 Use repeated addition. 6×7 6, the first factor, tells 6×7 how many times to add. = 7 + 7 + 7 + 7 + 7 + 7 = 42 7, the second factor, tells which number to add. Copyright © The McGraw-Hill Companies, Inc. Use an array. Find each product. 1. 5 × 3 2. 4 × 6 3. 9 × 3 4. 7 × 5 5. 7 × 1 6. 3 × 6 7. 8 × 2 8. 6 × 9 9. 3 × 3 = 10. 9 × 2 = 11. 4 × 8 = 12. 1 × 6 = Name Use repeated addition. Find each product. 13. 7 × 2 14. 8 × 8 15. 3 × 7 Lesson 16. 17. 6 × 3 = 18. 2 × 1 = 19. 5 × 6 = 20. 7 × 9 = 5 × 9 5-G 21. 8 × 1 22. 4 × 0 23. 3 × 5 24. 7 × 7 25. 9 × 1 26. 8 × 5 27. 1 × 4 28. 5 × 2 29. 3 × 9 30. 7 × 4 31. 0 × 8 32. 6 × 8 33. 5 × 5 34. 7 × 9 35. 4 × 4 36. 5 × 1 37. 0 × 6 = 38. 5 × 5 = 39. 1 × 4 = 40. 7 × 8 = 41. 4 × 7 = 42. 8 × 9 = 43. 5 × 0 = 44. 6 × 7 = Copyright © The McGraw-Hill Companies, Inc. Find each product. USING LESSON 5-G Name Multiplication Facts Lesson 5-G Lesson Goal Use an array. • Find products of basic multiplication facts. Draw a picture or use counters. What Can I Do? I want to find the product of two numbers. What the Student Needs to Know 7, the second factor, tells the number in each row. • Add a 1- digit number to a 1- or 2- digit number. • Skip-count by numbers 2 through 9. • Recognize multiplication as repeated addition. Count to find the product. What Can I Do? Read the question and the response. Then have students look over the first example. • How many rows of counters are in the array? (6) How many counters are in each row? (7) • Skip count to find the number of counters in all. 7, 14, . . . (21, 28, 35, 42) What is the product of 6 × 7? (42) 6 × 7= 42 Use repeated addition. 6×7 6, the first factor, tells 6×7 how many times to add. = 7 + 7 + 7 + 7 + 7 + 7 = 42 7, the second factor, tells which number to add. Getting Started Use an array. Find each product. Copyright © The McGraw-Hill Companies, Inc. Have students skip count with you. Say: • I want to count by 5s. Count with me. 5, 10, 15, 20, 25, 30. What number comes next? (35) How did you find that number? (I added 5 to the last number.) • To get to 35 starting from 0, how many times did you add 5? (7 times) Demonstrate and array of 7 rows of 5 counters each. Say: • How many counters are in each row? (5) How many rows of counters? (7) How many counters in all? (35) Can you write this as a multiplication fact? (7 × 5 = 35) Repeat the activity with other basic multiplication facts, such as 8 × 3 and 2 × 9. 6×7 6, the first factor, tells the number of rows. 1. 5 × 3 15 2. 4 × 6 24 3. 9 × 3 27 4. 7 × 5 35 5. 7 × 1 7 6. 3 × 6 18 7. 8 × 2 16 8. 6 × 9 54 9. 3 × 3 = 9 11. 4 × 8 = 32 10. 9 × 2 = 18 12. 1 × 6 = 6 159_160_S_G4_C05_SI_119816.indd 159 7/9/12 2:59 PM WHAT IF THE STUDENT NEEDS HELP TO Add a 1-Digit Number to a 1- or 2-Digit Number Skip Count by Numbers 2 through 9 • Have the students use flash cards or mental math to practice addition facts on a daily basis, until he or she knows the sums of basic facts by rote. • Once the student has demonstrated a mastery of basic facts, have him or her practice adding a 1-digit number to a 2-digit number every day for 5–10 minutes. • Have the student use a number line or counters to practice skip counting by numbers 2–9. After enough practice, the student should be able to use counting on to find the next number in each sequence. Name Use repeated addition. Find each product. 13. 14. 7 × 2 14 8 × 8 64 15. Lesson 16. 3 × 7 21 5 × 9 45 17. 6 × 3 = 18 18. 2 × 1 = 19. 5 × 6 = 30 20. 7 × 9 = 63 5-G Have the student look over the second example. • What number do you add? (the second factor; 7) How many times do you add that number? (the number shown by the first factor; 6) Add the numbers together two at a time. What sums do you get? (7 + 7 = 14; 14 +7 =21; 21 + 7 = 28; 28 + 7 = 35; 35 + 7 = 42) • How is this pattern like counting? (It is the same as skip counting.) What is the product of 6 × 7? (42) 2 Find each product. 8 × 1 8 22. 4 × 0 0 23. 3 × 5 15 24. 7 × 7 49 25. 9 × 1 9 26. 8 × 5 40 27. 1 × 4 4 28. 5 × 2 10 29. 3 × 9 27 30. 7 × 4 28 31. 0 × 8 0 32. 6 × 8 48 33. 5 × 5 25 34. 7 × 9 63 35. 4 × 4 16 36. 5 × 1 5 37. 0 × 6 = 0 38. 5 × 5 = 25 39. 1 × 4 = 4 40. 7 × 8 = 56 41. 4 × 7 = 28 42. 8 × 9 = 72 43. 5 × 0 = 44. 6 × 7 = 42 0 Try It Copyright © The McGraw-Hill Companies, Inc. 21. 159_160_S_G4_C05_SI_119816.indd 160 7/9/12 3:00 PM WHAT IF THE STUDENT NEEDS HELP TO Recognize Multiplication as Repeated Addition Complete the Power Practice • Have the student practice multiplying using arrays. First, have the student model 4 groups of 6 counters each, without putting them in rows. Students can repeatedly add 6 four times to find the total. Next, have the student arrange the counters in an even array of 4 rows of 6 counters each and find the total using skip counting and counting by 1s. Finally, have him or her write an addition sentence and a multiplication sentence for the array. • Discuss each incorrect answer with the student. Have the student make an array of each exercise using counters. Be sure the student correctly identifies the factor that shows the number of rows and the number of counters in each row. Provide counters for students. Ask • Look at the first exercise. How many rows of counters will you make? (5) How many counters in each row? (3) What is the product of 5 × 3? (15) Have the student complete Exercises 2–12. Then ask: • Look at Exercise 13. What number will you repeatedly add? (2) How many times will you add that number? (7 times) What is the product of 7 × 2? (14) • Continue to check students’ understanding of the multiplication process and how it relates to building arrays, repeated addition, and skip-counting. • Students who have difficulty relating the vertical form of multiplication to the horizontal can be asked to read the exercises aloud. Power Practice • Have students complete the practice items. Then review each answer. • Ask volunteers to describe how they solved selected exercises. Discuss which method might work better when the factors are greater numbers and which is better when the factors are lesser numbers. Stress that both methods are equally valid. Lesson 5-G Name Round to the Nearest Ten Lesson 5-H Use a number line. What Can I Do? I want to round a number to the nearest ten. The number 18 is between 10 and 20. It is closer to 20. So, 18 rounds up to 20. 10 11 12 13 14 15 16 17 18 19 20 The number 32 is between 30 and 40. It is closer to 30. So, 32 rounds down to 30. 30 31 32 33 34 35 36 37 38 39 40 Use the ones digit. If the ones digit is less than 5, round down. If it is 5 or greater, round up. Copyright © The McGraw-Hill Companies, Inc. Round 64 down to 60. Round 65 up to 70. Use the number line. Round to the nearest ten. 1. 51 2. 17 3. 34 50 51 10 52 53 54 55 56 57 58 59 60 11 12 13 14 15 16 17 18 19 30 31 32 33 34 35 36 37 38 39 20 40 Name 4. 81 5. 24 6. 38 7. 62 8. 33 9. 74 10. 45 11. 13 12. 9 13. 78 14. 65 15. 44 16. 26 17. 77 18. 88 Lesson 5-H Copyright © The McGraw-Hill Companies, Inc. Look at the ones digit. Round each number to the nearest ten. USING LESSON 5-H Name Round to the Nearest Ten Lesson Goal Lesson 5-H Use a number line. • Round numbers to the nearest ten. What Can I Do? I want to round a number to the nearest ten. What the Student Needs to Know The number 18 is between 10 and 20. It is closer to 20. So, 18 rounds up to 20. 10 • Count by 10s. • Read a number line. • Identify the ones digit. 11 12 13 14 15 16 17 18 19 20 The number 32 is between 30 and 40. It is closer to 30. So, 32 rounds down to 30. Getting Started 30 31 • Have students count by 10s to 100. • Display a hundred chart and have students locate the 10s. (10, 20, 30, . . . 100) 32 33 34 35 36 37 38 39 40 Use the ones digit. If the ones digit is less than 5, round down. If it is 5 or greater, round up. Round 64 down to 60. Round 65 up to 70. Read the question and the response. Then read and discuss the examples. Ask: • What does it mean when you say “18 rounds up to 20”? (20 is the nearest ten to 18, and it is greater, so you have to round up.) • What does it mean when you say “32 rounds down to 30”? (30 is the nearest ten to 32, and it is less, so you have to round down.) • Would you round 55 up or down? Why? (Up; you round up when the ones digit is 5 or greater.) Copyright © The McGraw-Hill Companies, Inc. What Can I Do? Use the number line. Round to the nearest ten. 1. 51 50 2. 17 20 3. 34 30 50 51 10 52 53 54 55 56 57 58 59 60 11 12 13 14 15 16 17 18 19 30 31 32 33 34 35 36 37 38 39 20 40 163_164_S_G4_C05_SI_119816.indd 163 7/9/12 3:07 PM WHAT IF THE STUDENT NEEDS HELP TO Count by 10s Read a Number Line • Give the student 10 play dimes and have the student count by tens to 1 dollar. • Have the student use base-ten blocks to show the tens from 10 to 100. Then have the student count the blocks by tens. • Draw a 0–10 number line on the board. Have the student locate a number you say, the number that is 1 less, and the number that is 1 greater. Name Look at the ones digit. Round each number to the nearest ten. 4. 81 80 5. 24 20 6. 38 40 7. 62 60 8. 33 30 9. 74 70 10. 45 50 11. 13 10 12. 9 Lesson 5-H Try It Suggest that students use these steps: • Find the number on the number line. • Find the tens on either side of that number. • Decide which ten is closer to the number. • Write that ten. 10 Power Practice 80 14. 65 70 15. 44 40 16. 26 30 17. 77 80 18. 88 90 Copyright © The McGraw-Hill Companies, Inc. 13. 78 • Have students complete the practice items. Then review each answer. • If students have trouble, they might draw a number line to help them. 163_164_S_G4_C05_SI_119816.indd 164 Learn with Partners & Parents 7/9/12 3:08 PM WHAT IF THE STUDENT NEEDS HELP TO Identify the Ones Digit • Have the student practice identifying the ones digit by writing the numbers in Exercises 4–18 in place-value charts. Complete the Power Practice Have students use the ages of people in their families to practice rounding to the nearest ten. • Give each student a hundred chart to take home. • Have students circle numbers on the hundred chart that represent family members‘ ages. • Tell students to round each family member‘s age to the nearest ten and write a sentence for each person; for example, To the nearest ten, Grandpa Dennis is 70. To the nearest ten, I am 10. • Review the rules for rounding: round down if the ones digit is 0–4; round up if the ones digit is 5–9. • Have the student circle the ones digit before rounding the number. Lesson 5-H Name Compare Numbers with Two- and Three-Digits Lesson 5-I Start at the left. Compare the digits. What Can I Do? I want to compare two whole numbers. If one number has more digits, it is greater. 469 482 same 468 > 42 > means is greater than. Compare the hundreds digit. Then compare tens digits. < means is less than. 6 < 8, so 469 < 482. Circle the number that is greater. 1. 91 or 204 2. 63 or 36 3. 710 or 107 4. 454 or 544 7. 856 or 865 8. 505 or 55 Circle the number that is less. Copyright © The McGraw-Hill Companies, Inc. 5. 24 or 214 6. 11 or 17 Compare. Use > or <. 9. 96 10. 415 405 11. 64 13. 113 130 14. 667 646 15. 961 17. 132 232 18. 73 21. 24 86 42 22. 329 37 332 42 12. 611 496 916 16. 312 231 19. 491 419 20. 18 23. 202 222 24. 323 183 328 USING LESSON 5-I Name Compare Numbers with Two- and Three-Digits Lesson Goal • Compare two- and three-digit whole numbers. Compare the digits. What Can I Do? I want to compare two whole numbers. What the Student Needs to Know Try It • Have students read the directions for the two sets of exercises. • Then have students find those exercises in which the two numbers have a different number of digits. Ask: Why are these exercises easier than the others? (The number with more digits is always greater.) Power Practice • Remind students that the smaller, pointed part of the > or < symbol always points to the number that is less. 469 482 > means is greater than. Compare the hundreds digit. Then compare tens digits. < means is less than. 6 < 8, so 469 < 482. 1. 91 or 204 2. 63 or 36 3. 710 or 107 4. 454 or 544 7. 856 or 865 8. 505 or 55 Circle the number that is less. 5. 24 or 214 Copyright © The McGraw-Hill Companies, Inc. Read the question and the response. Then read and discuss the examples. Ask: • What numbers are being compared in the first example? (468 and 42) Which number is greater and how do you know? (468, because it has the hundreds digit) • In the second example, do you use the hundreds digits? (Yes, the hundreds digits are the same. So, compare the tens digits.) Start at the left. Circle the number that is greater. Getting Started What Can I Do? 5-I same 468 > 42 • Compare one-digit numbers. • Use the > and < symbols. • Identify ones, tens, and hundreds digits. • Write 40 on the board. Say: Name a number less than 40. What number sentence can you write to show your number is less than 40? (If students choose 20, for example, they write 20 < 40.) • Now write a number sentence that shows 40 is greater than your number. (For example, 40 > 20.) If one number has more digits, it is greater. Lesson 6. 11 or 17 Compare. Use > or <. 9. 96 > 86 10. 415 > 405 11. 64 > 42 12. 611 > 496 13. 113 < 130 14. 667 > 646 15. 961 > 916 16. 312 > 231 17. 132 < 232 18. 73 > 37 19. 491 > 419 20. 18 < 183 21. 24 < 42 23. 202 < 222 24. 323 < 328 22. 329 < 332 167_S_G4_C05_SI_119816.indd 167 09/07/12 7:23 PM WHAT IF THE STUDENT NEEDS HELP TO Compare One-Digit Numbers Identify Ones, Tens, and Hundreds Digits • Write 8 and 2 on the board. Ask the student which number is greater. Write the sentence “Eight is greater than two.” Have the student change this to math symbols: 8 > 2. Repeat, using the sentence “Two is less than eight.” • Provide worksheets with blank place-value charts. • Have the student use a set of 0–9 digit cards. He or she should choose cards and write digits in a chart. When the charts are complete, have the student read the numbers and tell the place names of the digits. Use the > and < Symbols • Write the > and < symbols on the board and review their meanings. • Provide number cards and cards with the > and < symbols. Have students work in small groups to make and read comparison sentences. Complete the Power Practice • Provide base-ten blocks. Have the students work in pairs to show the numbers. Name Multiplication with Regrouping Lesson 5-J Use basic facts and regrouping. What Can I Do? 48 × 7 I want to multiply by a 1-digit number. Multiply the ones digit in the first factor by the second factor. Regroup if needed. 5 7 × 8 = 56 48 × 7 6 Then, multiply the tens digit in the first factor by the second. Add any regrouped tens. 5 7 × 4 = 28 28 + 5 = 33 48 × 7 336 Copyright © The McGraw-Hill Companies, Inc. Use basic facts and regrouping. Find each product. 1. 32 × 3 Think: 3 × 2 ones 3 × 3 tens 2. 61 × 5 Think: 5 × 1 ones 5 × 6 tens 3. 48 × 4 Think: 4 × 8 ones 4 × 4 tens 16 tens + 3 tens Find each product. 4. 93 × 7 8. 73 × 5 = 5. 22 × 4 9. 94 × 4 = 6. 25 × 6 7. 56 × 8 10. 83 × 9 = USING LESSON 5-J Name Multiplication with Regrouping Lesson 5-J Lesson Goal Use basic facts and regrouping. • Multiply a 2-digit number by a 1-digit number. What Can I Do? 48 × 7 I want to multiply by a 1-digit number. What the Student Needs to Know Multiply the ones digit in the first factor by the second factor. Regroup if needed. 5 • Recall basic multiplication facts. • Recognize 10 ones as 1 ten for regrouping. Then, multiply the tens digit in the first factor by the second. Add any regrouped tens. Getting Started What Can I Do? Have students read the question and the response. Then read and discuss the example. Ask: • What is the first step in finding the product of 48 × 7? (Multiply the 7 times the 8 in the ones place of the second factor.) What is that product? (56) • What is the next step? (Multiply the 7 times the 4 in the tens place of the first factor.) What is that product? (28) What else do you have to do? (You have to add the 5 regrouped tens.) What is that sum? (28 + 5 = 33) What is the next step? (Regroup the 30 tens as 3 hundreds.) Where do you write that in the answer? (Write the 3 tens under the tens, and the 3 hundreds to the left of the tens.) • What is 7 × 48? (336) Try It Have students read the directions and look at the first exercise. Ask: • When do you have to regroup to find the product? (You have to regroup when the product of the 1-digit factor and the ones or tens digit of the other factor is greater than 9.) Power Practice • Have students complete the practice items. Then review each answer. 5 7 × 4 = 28 28 + 5 = 33 48 × 7 336 Use basic facts and regrouping. Find each product. 1. Copyright © The McGraw-Hill Companies, Inc. Help students review multiplying multiples of 10. Ask: • I want to multiply 5 × 1. What is that product? (5) What is the product of 5 × 10? (50) • What is 2 × 4? (8) What is 2 × 40? (80) 7 × 8 = 56 48 × 7 6 32 × 3 96 Think: 3 × 2 ones 3 × 3 tens 2. 61 × 5 305 Think: 5 × 1 ones 5 × 6 tens 3. 48 × 4 192 Think: 4 × 8 ones 4 × 4 tens 16 tens + 3 tens Find each product. 4. 93 × 7 651 5. 8. 73 × 5 = 365 22 × 4 88 6. 25 × 6 150 9. 94 × 4 = 376 7. 56 × 8 448 10. 83 × 9 = 747 169_S_G4_C05_SI_119816.indd 169 7/9/12 3:26 PM WHAT IF THE STUDENT NEEDS HELP TO Recall Basic Multiplication Facts • Have the student use arrays or repeated addition to find the products of multiplication facts. The student should practice finding the products of these facts for about 10 minutes each day. Recognize 10 Ones as 1 Ten for Regrouping • Have the student work with base-ten blocks. Have him or her model addition that will result in regrouping, for instance 7 + 8. • Help the student see that the sum 15 can be regrouped as 1 ten and 5 ones. Point out that there are the same number of units in 10 ones as in 1 ten. Complete the Power Practice • Discuss each incorrect or incomplete answer with the student. Have the student name the product of each fact within the exercise. • Have the student write each partial product, then add to find the final product.
© Copyright 2026 Paperzz