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. ____
Answer:
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.
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?
Answer:
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. ___ × ___
Answer:
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.
Answer:
Therefore, 76 x 27 approximately equals 2,052.
D. How can you check to see if the product is reasonable?
Answer:
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: ___
Answer:
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: _____
Answer:
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: ____
Answer:
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.
On Your Own
Question 4.
Reason David wrote that the product of 69 and 52 is 4,318. Is his answer reasonable? Explain.
_______________________________
_______________________________
_______________________________
Answer:
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? ____
Answer:
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: ____
Answer:
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: _____
Answer:
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: ___
Answer:
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: ___
Answer:
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: ___
Answer:
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: ___
Answer:
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?
Answer:
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?
__________________________
Answer:
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: ____
Answer:
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: ____
Answer:
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: ____
Answer:
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: ____
Answer:
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: ____
Answer:
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: ____
Answer:
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.
Answer:
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.