We included HMH Into Math Grade 4 Answer Key PDF Module 8 Lesson 6 Choose a Multiplication Strategy to make students experts in learning maths.
I Can fluently multiply two 2-digit numbers using the method of my choice.
Step It Out
1. Most professional soccer matches require 14 soccer balls. The traditional soccer ball has 32 panels, each representing one country in Europe. How can you multiply using partial products to find out how many panels are on 14 traditional soccer balls?
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Answer:
Given,
Most professional soccer matches require 14 soccer balls.
The traditional soccer ball has 32 panels, each representing one country in Europe.
Estimation :
32 is near to 30
14 is near to 15
So, 32 x 14 = 30 x 15 = 450
Therefore, the total number of panels approximately equals 450.
Actual :
So, total Number of panels = number of soccer balls x number of panels
the total number of panels = 32 x 14 =
Therefore, the total panels are on 14 traditional soccer balls are 448.
Yes. the answer is reasonable because the actual answer is approximately equal to the estimated product.
Turn and Talk How can you use the Distributive Property to solve the problem?
Step It Out
2. At the beginning of each season, the National Basketball Association sends each of the 29 American teams 72 basketballs. How can you multiply with regrouping to find out how many basketballs are sent?
D. How do you know if your answer is reasonable?
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Answer:
Given,
At the beginning of each season, the National Basketball Association sends each of the 29 American teams 72 basketballs.
Estimation :
total basketballs sent = number of teams x number of basket balls
total basketballs sent = 29 x 72
29 is near to 30
72 is near to 70
So, 29 x 72 = 30 x 70 = 2100
Therefore, total basketball sent are approximately equals 2100.
Actual:
total basketballs sent = number of teams x number of basket balls
total basketballs sent = 29 x 72 =
Therefore, total basketballs sent are 2,088
Yes, the answer is reasonable because the actual answer is approximately equal to the estimated product.
Check Understanding Math Board
Question 1.
For each Championship Bowl, 76 footballs are used. How many footballs have been used in 52 Championship Bowls?
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Answer:
Given,
For each Championship Bowl, 76 footballs are used.
There are 52 champion bowls.
So, total footballs = number of footballs x number of championship bowls.
total footballs = 52 x 76 =
Therefore, total footballs are 3,952.
Estimate. Then choose a method to find the product.
Question 2.
Estimate: ___
Answer:
37 is near to 40
26 is near to 30
So, 37 x 26 = 40 x 30 = 1200
Therefore, 37 x 26 approximately equals 1,200.
Actual product = 37 x 26 =
Therefore, value of 37 x 26 = 962.
Question 3.
Estimate: ____
Answer:
82 is near to 80
49 is near to 50
So, 82 x 49 = 80 x 50 = 4000
Therefore, 82 x 49 approximately equals 4,000.
Actual product = 82 x 49 =
Therefore, value of 82 x 49 is 4,018.
Question 4.
Estimate: ____
Answer:
91 is near to 90
77 is near to 80
So, 91 x 77 = 90 x 80 = 7200
Therefore, 91 x 77 approximately equals 7,200.
Actual product = 91 x 77 =
Therefore, value of 91 x 77 is 7,007.
On Your Own
Question 5.
Model with Mathematics A bag of frozen strawberries contains 91 strawberries. How many strawberries are in 76 bags?
A. Use partial products to find the product.
76 × 91 = ___
Answer:
76 x 91 = ( 90 x 70 ) + ( 90 x 6 ) + ( 1 x 70 ) + ( 1 x 6 )
= 6300 + 540 + 70 + 6 = 6,916
B. Draw a picture to check your work.
Answer:
Therefore, value of 76 x 91 is 6,916.
Estimate. Then choose a method to find the product.
Question 6.
Estimate : ___
Answer:
43 is near to 40
35 is near to 40
So, 43 x 35 = 40 x 40 = 1,600
Therefore, 43 x 35 approximately equals 1,600.
Actual product = 43 x 35 =
Therefore, value of 43 x 35 is 1,505.
Question 7.
Estimate: ___
Answer:
59 is near to 60
18 is near to 20
So, 59 x 18 = 60 x 20 = 1,200
Therefore, 59 x 18 approximately equals 1,200.
Actual product = 59 x 18 =
Therefore, value of 59 x 18 is 1,062.
Question 8.
Estimate: ____
Answer:
86 is near to 90
72 is near to 70
So, 86 x 72 = 90 x 70 = 6,300
Therefore, 86 x 72 approximately equals 6,300.
Actual product = 86 x 72 =
Therefore, value of 86 x 72 is 6,192.
Question 9.
Josie picks 13 berries from each of 23 blueberry bushes. How many berries does she pick?
Answer:
Given.
Josie picks 13 berries from each of 23 blueberry bushes.
So, total berries = number of berries x number of blueberry bushes
total berries = 13 x 23 =
Therefore, she picked 299 total berries.
Question 10.
Use Repeated Reasoning Why is the second partial product greater than the first partial product when you multiply two 2-digit numbers with regrouping?
Answer:
The second partial product is greater than the first partial product when you multiply two 2-digit numbers with regrouping because, now we are multiplying a number with a value in its tens place, when before we were multiplying a number with only a value in the one’s place.
On Your Own
Question 11.
Construct Arguments A scientific calculator has 54 keys. There are 68 of that type of scientific calculator in the resource room. Gina wondered how many keys that is.
- Use partial products to find the product.
54 × 68 = ____ - Use the Distributive Property to check your work.
Answer:
54 x 68 = ( 60 x 50 ) + ( 60 x 4 ) + ( 8 x 50 ) + ( 8 x 4 )
= 3000 + 240 + 400 + 32 = 3,672.
The product value is same i.e., 54 x 68 = 68 x 54 . Hence, distributive property is verified.
Question 12.
Reason An order was placed for new flags for the color guard. The flags cost $34 each. If the color guard director pays for 16 flags with six $100 bills, how much change will the director receive? How did you find the answer?
Answer:
Answer:
An order was placed for new flags for the color guard. The flags cost $34 each. The colors guard director pays for 16 flags with six $100 bills.
Tota cost = number of flags x cost of each flag
total cost = $34 x 16 =
Total paid = 6 x $100 = $600
So, balance = 600 – 544 = $56
Therefore, director receive $56 change.
Find the unknown digits. Complete the problem.
Question 13.
Answer:
Question 14.
Answer:
Question 15.
Answer:
Question 16.
Construct Arguments How do you know which of the following costs more, 38 sweaters at $49 each or 48 pairs of jeans at $39 each? _____
Answer:
Given,
38 sweaters at $49 each
So, cost = 38 x 49 =
38 x $49 = $1,862
48 pairs of jeans at $39
So, cost = 48 x 39 =
48 x $39 = $1,872
So, $1,872 > $1,862
Therefore, 48 pairs of jeans at $39 each cost more than 38 sweaters at $49 each.