We included **HMH Into Math Grade 3 Answer Key**** PDF** **Module 5 Lesson 2 Use the Associative Property of Multiplication** to make students experts in learning maths.

## HMH Into Math Grade 3 Module 5 Lesson 2 Answer Key Use the Associative Property of Multiplication

I Can use the Associative Property to find a product when one factor is a multiple of 10.

**Spark Your Learning**

Carma makes $4 each time she walks Mr. Kim’s dog, Ralphie. During 10 days last month, Carma

walked Ralphie 2 times each day.

To find her pay, Carma multiplies her pay for each day by 10, the number of days she worked.

Mr. Kim multiplies the pay for each walk by the number of walks for the month. Carma: 10

Using which method will Carma earn more? Explain.

**Turn and Talk** When you multiply 3 factors, does the order in which you group the factors matter?

**Build Understanding**

1. Lanie makes $40 for each bookcase she builds. How much does Lanie make for building 2 bookcases?

A. How can you rewrite 2 x 40 using 10 as a factor?

2 × 40 = __ × (__ × ___)

Answer:

2 × 40 = 2 × ( 4 × 10 )

B. How can you use the Associative Property to change the grouping of your factors?

2 × 40 = (__ × __) × ___

Answer:

2 × 40 = ( 2 × 4 ) × 10

**Connect to Vocabulary**

You have learned that the Associative Property of Multiplication states that when the grouping of the factors is changed, the product remains the same.

Example:

2 × (3 × 4) = (2 × 3) × 4

C. Find the product.

2 × 40 = ___ × ___ = ___

Lanie earns ___.

Answer: 80

2 × 40 = 40 × 2 = 80

by multiplying 40 with 2 we get 80

2. Nam pays a studio $5 a minute for video recording.

How much does she pay for 30 minutes of recording?

A. How can you rewrite 30 × 5 using 10 as a factor?

30 × 5 = (___ × __) × ___

Answer:

30 × 5 = ( 3 × 10 ) × 5

B. How can you use the Associative Property to regroup the factors?

30 × 5 = __ × (10 × ___)

Answer:

30 × 5 = 3 × (10 × 5 )

C. Use the Distributive Property to find the product.

30 × 5 = __ groups of (__ × __)

= (___ × ___) + (__ × __) + (__ × __)

= __ + __ + __ = ___

Nam pays ___ for 30 minutes of recording.

Answer:

30 × 5 = 3 groups of (10 × 5)

= (3 × 20) + (3 × 20) + (3 × 10)

= 60 + 60 + 30 = 150

**Step It Out**

3. Ashley sells 40 shirts at a thrift store for $6 each. How can you use the Associative and Distributive Properties to find how much money she takes in?

A. Rewrite 40 × 6 using 10 as a factor.

40 × 6 = (___ × 10) × ____

Answer:

40 × 6 = ( 4 × 10) × 6

B. Use the Associative Property.

40 × 6 = __ × (__ × ____)

Answer:

40 × 6 = 4 × ( 10 × 6 )

C. Use the Distributive Property.

40 × 6 = _____ groups of (__ × ___)

= (10 × 6) + (___ × ___) + (___ × ___) + (___ × ___)

= _____ + ___ + ___ + ____

Ashley takes in ____.

Answer:

40 × 6 = 6 groups of (10 × 4)

= (10 × 6) + (10 × 6) + (10 × 6) + (10 × 6)

= 60 + 60 + 60 + 60

= 240

Ashley takes in 240.

**Check Understanding Math Board**

Question 1.

Manny earns $30 each day washing cars. He works 3 days each week. How much does he earn in one week? ____

Answer:

Given,

Manny earns $30 each day washing cars.

He works 3 days each week.

30 × 3 = $90

Thus he earns $90 in one week.

**Show two ways to group the factors. Write the product.**

Question 2.

3 × 20 = 3 × (__ × ___)

= (___ × ___) × ___

= ____

Answer: 60

3 × 20 = 3 × ( 2 × 10)

= (3 × 2) × 10

= 60

Question 3.

2 × 50 = 2 × (___ × ___)

= (___ × ___) × ___

= ____

Answer: 100

2 × 50 = 2 × ( 5 × 10)

= ( 2 × 5 ) × 10

= 100

**On Your Own**

Question 4.

**Critique Reasoning** Jess finds 8 × 70 using 8 × (7 + 10). Is Jess correct? Explain.

Answer: wrong.

Given jess finds 8 × 70

using 8 × ( 7+10)

by solving 8 multiply with 7 + 10 we get 136.

as by multiplying given 8 with 70 we get 560.

hence jess is incorrect.

**Write the unknown number.**

Question 5.

3 × 60 = 3 × (__ × 10)

Answer: 6

3 × 60 = 3 × (6 × 10)

Question 6.

80 × 5 = (__ × 10) × 5

Answer: 8

80 × 5 = (8 × 10) × 5

**Show two ways to group the factors. Write the product.**

Question 7.

80 × 6 = (__ × ___) × ___

= ___ × (___ × ___)

= _____

Answer: 480

80 × 6 = ( 8 × 10) × 6

= 8 × (10 × 6 )

= 480

Question 8.

9 × 50 = (__ × ___) × ___

= ___ × (___ × ___)

= _____

Answer: 450

9 × 50 = (9 × 5) × 10

= 9 × ( 5 × 10)

= 150

Question 9.

**Use Structure** Sue practices the guitar 4 hours each week for 30 weeks. How many hours does Sue practice? Use the Associative Property and Distributive Property to solve. Show your work.

**I’m in a Learning Mindset!**

What do I do when I’m learning something new? What helps me remember what to do?

Answer:

Given,

Sue practices the guitar 4 hours each week for 30 weeks.

1 week = 4 hours

30 weeks = ?

4 × 30 = 120 hours

Distributive Property:

4 × 30 = 4 × (3 × 10)