# Into Math Grade 4 Module 8 Lesson 5 Answer Key Multiply with Regrouping

We included HMH Into Math Grade 4 Answer Key PDF Module 8 Lesson 5 Multiply with Regrouping to make students experts in learning maths.

## HMH Into Math Grade 4 Module 8 Lesson 5 Answer Key Multiply with Regrouping

I Can fluently multiply two 2-digit numbers using the method of regrouping.

Step It Out

1. A music store has 12 standard pianos on display. A standard piano has 88 keys. How many piano keys are in the display at the music store? Multiply. ___ × _____
Estimate. ____

Given,

A music store has 12 standard pianos on display.

A standard piano has 88 keys.

So, total piano keys = number of pianos x number of keys in each piano

i.e., total piano keys = 12 x 88

12 is near to 10

88 is near to 90

So, 12 x 88 = 10 x 90 = 900

Therefore, total piano keys are approximately equal to 900.

A. Write the problem vertically. Then use place value and regrouping to find the answer.  B. Where did you need to regroup? Why?
C. Why did you record a zero in the ones place of the second partial product?
__________________________
__________________________
__________________________

Turn and Talk How do you know if your answer is reasonable?

The product is approximately equal to the estimated product. So, the answer is reasonable.

Step It Out

2. Mrs. Singh is making a booklet of guitar music that contains 76 pages. She will need 27 copies of the booklet for her class. How many sheets of paper will she use to make the booklets? Multiply. ___ × ___

Given,

Mrs. Singh is making a booklet of guitar music that contains 76 pages.

She will need 27 copies of the booklet for her class.

total sheets of papers = number of pages x number of copies = 76 x 27

76 is near to 80

27 is near to 30

So, 76 x 27 = 30 x 80 = 2400.

Therefore, the total sheets of paper  approximately equals 2400.  Therefore, 76 x 27 approximately equals 2,052.

D. How can you check to see if the product is reasonable?

Yes. the product is reasonable because the estimated product is approximately equal to the actual product.

Turn and Talk How can you use regrouping to multiply?

Check Understanding Math Board

Estimate. Then find the product.

Question 1.
Estimate: ___ 88 is near to 90

63 is near to 60

So, 88 x 63 = 80 x 60 = 4800.

Therefore, 88 x 63 approximately equals 4800. Therefore, 88x 63 = 5,544.

Question 2.
Estimate: _____ 94 is near to 90

18 is near to 20

So, 94 x 18 = 90 x 20 = 1800.

Therefore, 94 x 18 approximately equals 1800. Therefore, 94 x 18 = 1,692.

Question 3.
Estimate: ____ 23 is near to 20

16 is near to 20

So, 23 x 16 = 20 x 20 = 400.

Therefore, 23 x 16 approximately equals 400. Therefore, 23 x 16 = 368.

Question 4.
Reason David wrote that the product of 69 and 52 is 4,318. Is his answer reasonable? Explain.
_______________________________
_______________________________
_______________________________

Given,

David wrote that the product of 69 and 52 is 4,318. His answer is not reasonable because 4,318 is not equal to 3,588.

Question 5.
Angelina is training for an ultra marathon. She will run a total of 22 miles a week for 28 weeks. How many miles will Angelina run? ____ Given,

Angelina is training for an ultra marathon.

She will run a total of 22 miles a week for 28 weeks.

The number of miles = Number of weeks x number of miles in each week.

Number of miles = 22 x 28 = Therefore, the Number of miles Angelina run is 616.

Estimate. Then find the product.

Question 6.
Estimate: ____ 64 is near to 60

28 is near to 30

So, 64 x 28 = 60 x 30 = 1800.

Therefore, 64 x 28 approximately equals 1800. Therefore, value of 64 x 28 is 1,792.

Question 7.
Estimate: _____ 66 is near to 70

79 is near to 80

So, 66 x 79 = 70 x 80 = 5600.

Therefore, 66 x 79 approximately equals 5600. Therefore, value of 66 x 79 = 5,214.

Question 8.
Estimate: ___ 89 is near to 90

49 is near to 50

So, 89 x 49 = 90 x 50 = 4500.

Therefore, 89 x 49 approximately equals 4500. Therefore, value of 89 x 49 is 4,361.

Question 9.
Estimate: ___ 73 is near to 70

84 is near to 80

So, 73 x 84 = 70 x 80 = 5600.

Therefore, 73 x 84 approximately equals 5600. Therefore, value of 73 x 84 is 6,132.

Question 10.
Estimate: ___ 55 is near to 50

39 is near to 40

So, 55 x 39 = 50 x 40 = 2000.

Therefore, 55 x 39 approximately equals 2000. Therefore, value of 55 x 39 is 2,145.

Question 11.
Estimate: ___ 94 is near to 90

56 is near to 60

So, 94 x 56 = 90 x 60 = 5400.

Therefore, 94 x 56 approximately equals 5400. Therefore, value of 94 x 56 is 5,264.

Question 12.
Twelve parents signed up to make 24 muffins each for the fifth-grade tea. How many muffins will there be for the tea?

Given,

Twelve parents signed up to make 24 muffins each for the fifth-grade tea.

Number of muffins = 12 x 24 = Therefore, total number of muffins = 288.

Question 13.
Music A harp is an instrument with 47 strings that run down at an angle to a soundboard. If a company builds 39 harps in a year, how many strings will they use? __________________________

Given,

A harp is an instrument with 47 strings that run down at an angle to a soundboard.

The company builds 39 harps in a year.

So, number of strings = 39 x 47 = Therefore, total number of strings they use are 1,833.

Estimate. Then find the product.

Question 14.
Estimate: ____ 34 is near to 30

31 is near to 30

So, 34 x 31 = 30 x 30 = 900.

Therefore, 34 x 31 approximately equals 900. Thereofore, value of 34 x 31 is 1,054.

Question 15.
Estimate: ____ 84 is near to 80

27 is near to 30

So, 89 x 27 = 80 x 30 = 2400.

Therefore, 89 x 27 approximately equals 2400. Therefore, value of 89 x 27 is 2,403.

Question 16.
Estimate: ____ 56 is near to 60

71 is near to 70

So, 56 x 71 = 60 x 70 = 4200.

Therefore, 56 x 71 approximately equals 4200. Therefore, value of 56 x 71 is 3,976.

Question 17.
Estimate: ____ 48 is near to 50

19 is near to 20

So, 48 x 19 = 50 x 20 = 1000.

Therefore, 48 x 19 approximately equals 1000. Therefore, value of 48 x 19 is 912.

Question 18.
Estimate: ____ 32 is near to 30

64 is near to 60

So, 32 x 64 = 30 x 60 = 1800.

Therefore, 32 x 64 approximately equals 1800. Therefore, value of 32 x 64 is 2,048.

Question 19.
Estimate: ____ 96 is near to 100

82 is near to 80

So, 96 x 82 = 100 x 80 = 8000.

Therefore, 96 x 82 approximately equals 8000. Therefore, value of 96 x 82 is 7,872.

Question 20.
Construct Arguments Eli makes 28 decorative bookmarks for his classmates. It takes 75 centimeters of yarn to make each bookmark. How much yarn does Eli use? Explain how you used regrouping to solve the problem.

Given,

Eli makes 28 decorative bookmarks for his classmates.

It takes 75 centimeters of yarn to make each bookmark. Therefore, Eli uses 2,100 centimeters of Yarn.

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