All the solutions provided in McGraw Hill Math Grade 5 Answer Key PDF Chapter 2 Lesson 6 Use Partial Products and the Distributive Property will give you a clear idea of the concepts.
McGraw-Hill My Math Grade 5 Answer Key Chapter 2 Lesson 6 Use Partial Products and the Distributive Property
Draw It
Darnel and his four friends went to an ice skating rink and bought sandwiches. They divided the total cost and found that each person needs to pay $17. What was the total cost for ice skating and sandwiches?
Find 5 × 17 using an area model.
1. Label the model to find the partial products.
Answer:
2. Add the partial products.
___ + ___ = ____
So, the total cost for ice skating and sandwiches was _____.
Answer:
The partial products are 50 + 35 = 85
So, the total cost for ice skating and sandwiches was 85.
When you use partial products, you are using a property. A property is a rule in mathematics that can be applied to all numbers. The property that you applied above is called the Distributive Property. You will learn more about this property in the next lesson.
Try It
Find 7 × 56 using an area model.
1. Label the model to find partial products.
Answer:
2. Multiply. Then add.
7 × 56 = (7 × 50) + (7 × ___)
= ____ + ____
= _____
So, 7 × 56 = ____
Answer:
392
Explanation:
7 × 56 = (7 × 50) + (7 × 6)
= 350 + 42
= 392
So, 7 × 56 = ____
392
Talk About It
Question 1.
Mathematical PRACTICE 3 Draw a Conclusion How do area models show partial products?
Answer:
Question 2.
In finding 7 × 56 above, why does the area model separate 56 into 50 and 6?
Answer:
The area model separates 56 into 50 and 6 to calculate the multiplication easily.
Question 3.
Find 6 × 36 using partial products. Label the model to help you solve. Show your work.
Answer:
Practice It
Multiply using the area model. Label each model.
Question 4.
4 × 16 = ____
Answer:
64
Explanation:
Question 5.
6 × 81 = ____
Answer:
486
Explanation:
Question 6.
7 × 29 = ___
Answer:
203
Explanation:
Question 7.
5 × 39 = ___
Answer:
195
Explanation:
Apply It
Question 8.
Ronnie swims 4 laps each day at the pool. How many laps does he swim in 28 days? Use an area model to solve.
Answer:
4 × 28 = 112
Explanation:
4 × 20 + 4 × 8
80 + 32
112
Question 9.
Mathematical PRACTICE Model Math Yoshi saved $5 each week for 23 weeks. What is the total amount of money he saved? Use an area model to solve.
Answer:
5 × 23 = 115
Explanation:
5 × 20 + 5 × 3
100 + 15
115
Question 10.
Thirty-eight fish are in each aquarium at a fish store. How many fish are there in five aquariums? Use an area model to solve.
Answer:
38 × 5 = 190
Explanation:
Question 11.
Mathematical PRACTICE Find the Error Omar was using an area model to find 4 × 61. Find his mistake and correct it.
(4 × 60) + (4 × 10) = 240 + 40 = 280
Answer:
The answer is 244, not 280.
Explanation:
(4 × 60) + (4 × 1)
240 + 4
244
Write About It
Question 12.
How can area models be used to solve multiplication problems?
Answer:
McGraw Hill My Math Grade 5 Chapter 2 Lesson 6 My Homework Answer Key
Practice
Question 1.
Multiply 2 × 27 using the area model. Label the model.
2 × 27 = _____
Answer:
54
Explanation:
2 × 20 + 2 × 7
40 + 14
54
Question 2.
Multiply 9 × 43 using the area model. Label the model.
9 × 43 = _____
Answer:
387
Explanation:
9 × 40 + 9 × 3
360 + 27
387
Problem Solving
Question 3.
A pet store has eighteen hamsters in each cage. How many hamsters are there in six cages? Usé an area model to solve.
Answer:
18 × 6 = 108
Explanation:
6 × 10 + 6 × 8
60 + 48
108
Question 4.
Mathematical PRACTICE 4 Model Math Brandon packs his lunch 4 days each week. How many days does he pack his lunch for 36 weeks? Use an area model to solve.
Answer:
Bradon packs 144 days in 36 weeks.
Explanation:
We need to find the number of days he packs his lunch for 36 weeks.
4 × 36 = 144
The area model is shown in figure
4 × 36 = (4 × 30) + (4 + 6)
= 120 + 24
= 144
Question 5.
Ricarda earns a $25 allowance each week. How much allowance will she earn after 7 weeks? Use an area model to solve.
Answer:
$175
Explanation:
Ricarda earns a $25 allowance each week.
5 × 7 = 35
20 × 7 = 140
140 + 35 = 175
The allowance will she earn after 7 weeks is $175.
Question 6.
Write an expression that uses partial products to multiply 8 × 64.
Answer:
(80 × 6) + (8 × 4)