# McGraw Hill My Math Grade 3 Chapter 8 Lesson 4 Answer Key Multiply by 8

All the solutions provided in McGraw Hill Math Grade 3 Answer Key PDF Chapter 8 Lesson 4 Multiply by 8 will give you a clear idea of the concepts.

## McGraw-Hill My Math Grade 3 Answer Key Chapter 8 Lesson 4 Multiply by 8

Math in My World

Example 1
There are 6 trees along a street. In each tree, there are 8 birds. How many birds are there altogether? Find 6 × 8.
Each tree has a group of 8 birds.
One Way Draw an array.
Another way Draw a picture.
Use an X for each bird.  There are ____ birds altogether.
Check
The Commutative Property shows that 6 × 8 has the same product as 8 × 6. Since 8 × 6 = ___, then 6 × 8 = ____.
The 4s facts are helpful in remembering the 8s facts.

Given that,
There are 6 trees along a street.
In each tree there are 8 birds.
Each tree has a group of 8 birds. The array of 6 x 8 is The picture is The Commutative Property shows that 6 × 8 has the same product as 8 × 6.
Since 8 × 6 = 48, then 6 × 8 = 48.

Example 2
Pearl counted 5 honeybees on each of 8 flowers. How many honeybees are there altogether? Write a number sentence with a symbol for the unknown.
Find 5 × 8 = . Decompose 8 into equal addends of 4 + 4. So, 5 × 8 = ____
The unknown is ____
There are ___ honeybees.

Given that,
Pearl counted 5 honeybees on each of 8 flowers.
The total number of honeybees are So, 5 × 8 = 40.
The unknown is 40.
There are 40 honeybees.

Talk Math
There are 4 groups of 8 students and 8 groups of 8 students, how many students are there altogether? Explain. Given that,
4 groups of 8 students means 4 x 8 = 32.
There are 32 students in 4 groups.
8 groups of 8 students means 8 x 8 = 64.
There are 64 students in 8 groups.
The total number of students all together is 32 + 64 = 96.

Guided Practice

Complete the steps to find 7 × 8.

Question 1.
Label the array. Multiplication of 7 with 8 then you get 56.
Convert 8 into 4 + 4.
7 x 4 = 28.
7 x 4 = 28.
28 + 28 = 56. Question 2.
Double a known fact. So, 7 × 8 = ____
Multiplication of 7 with 4 then you get 28.
The product is 28.
Double the product is 28 + 28 = 56.
So, 7 x 8 = 56.

Independent Practice

Double a known fact to find each product.

Question 3.
3 × 8 = ____
3 × ___ = ____
3 × ____ = ____
___ + ____ = ____
Multiplication of 3 with 8 then you get 24.
3 x 8 = 24.
convert 8 into 4 + 4.
3 x 4 = 12.
3 x 4 = 12.
Therefore 12 + 12 = 24.

Question 4.
10 × 8 = ____
Multiplication of 10 with 8 then you get 80.
10 x 8 = 80.
Convert 8 into 4 + 4.
10 x 4 = 40.
10 x 4 = 40.
Therefore 40 + 40 = 80.

Question 5.
8 × 8 = ____
Multiplication of 8 with 8 then you get 64.
8 x 8 = 64.
Convert 8 into 4 + 4.
8 x 4 = 32.
8 x 4 = 32.
Therefore 32 + 32 = 64.

Question 6.
9 × 8 = ___
Multiplication of 9 with 8 then you get 72.
9 x 8 = 72.
Convert 8 into 4 + 4
9 x 4 = 36.
9 x 4 = 36.
Therefore 36 + 36 = 72.

Use the Commutative Property to find each product. Write a related multiplication fact.

Question 7.
1 × 8 = ___
Commutative property states that if change in order of the numbers in multiplication the product does not change.
Multiplication of 1 with 8 then you get 8.
1 x 8 = 8.
Multiplication of 8 with 1 then you get 8.
8 x 1 = 8.

Question 8.
0 × 8 = ____
Commutative property states that if change in order of the numbers in multiplication the product does not change.
Multiplication of 0 with 8 then you get 0.
0 x 8 = 0.
Multiplication of 8 with 0 then you get 0.
8 x 0 = 0.

Question 9.
6 × 8 = ____
Commutative property states that if change in order of the numbers in multiplication the product does not change.
Multiplication of 6 with 8 then you get 48.
6 x 8 = 48.
Multiplication of 8 with 6 then you get 48.
8 x 6 = 48.

Question 10.
7 × 8 = ___
Commutative property states that if change in order of the numbers in multiplication the product does not change.
Multiplication of 7 with 8 then you get 56.
7 x 8 = 56.
Multiplication of 8 with 7 then you get 56.
8 x 7 = 56.

Question 11.
2 × 8 = ___
Commutative property states that if change in order of the numbers in multiplication the product does not change.
Multiplication of 2 with 8 then you get 16.
2 x 8 = 16.
Multiplication of 8 with 2 then you get 16.
8 x 2 = 16.

Question 12.
4 × 8 = ___
Commutative property states that if change in order of the numbers in multiplication the product does not change.
Multiplication of 4 with 8 then you get 32.
4 x 8 = 32.
Multiplication of 8 with 4 then you get 32.
8 x 4 = 32.

Algebra Find each unknown factor. Use the Commutative Property.

Question 13.
8 × = 64 × 8 = 64
The unknown is ____.
Multiplication of 8 with 8 then you get 64.
8 x 8 = 64.
8 x 8 = 64.
The unknown is 8.

Question 14. × 1 = 8
1 × = 8
The unknown is ____.
Multiplication of 8 with 1 then you get 8.
8 x 1 = 8.
1 x 8 = 8.
The unknown is 8.

Question 15.
8 × = 72 × 8 = 72
The unknown is ____.
Multiplication of 8 with 9 then you get 72.
8 x 9 = 72.
9 x 8 = 72.
The unknown is 9.

Multiply.

Question 16. Multiplication of 0 with 8 then you get 0.
0 x 8 = 0. Question 17. Multiplication of 8 with 3 then you get 24.
8 x 3 = 24. Question 18. Multiplication of 5 with 8 then you get 40.
5 x 8 = 40. Question 19. Multiplication of 6 with 8 then you get 48.
6 x 8 = 48. Problem Solving

Mathematical PRACTICE 1 Make a Plan Use the following information to solve Exercises 20-22.

Mrs. Miller’s class of 8 students want to have one or more classroom pets.

Question 20.
If each student brought in 3 goldfish, how many goldfish would they have in the classroom?
Given that,
The total number of students in the class room is 8.
The total number of goldfish brought by students are 3.
So, 8 x 3 = 24.
Therefore there are 24 goldfish in the classroom.

Question 21.
If each student brought in 2 hamsters, how many hamsters would they have in the classroom?
Given that,
The total number of students in the class room is 8.
The total number of hamsters brought by the students are 2.
So, 8 x 2 = 16.
Therefore there are 16 hamsters in the classroom.

Question 22.
A pet store charges $10 for a lizard. If each student pays$5, how many lizards would they be able to purchase?
Given that,
The total number of students in the class room is 8.
The pet store charges for a lizard is $10. The each student pays$5.
The 8 students collect is 8 x $5 = 40. So, The number of lizards are 40/10 = 4. Therefore the number of lizards purchase by students are 4. HOT Problems Question 23. Mathematical PRACTICE 2 Use Number Sense The row that represents the products of 8 from the multiplication table is shown below. Describe one pattern in the products of 8. Will this pattern continue? Explain. Answer: One patten is multiplies of 8 having 8, 6, 4, 2, 0 in the ones place and all the products of of the 8 are even. This this patten will continue. Question 24. ? Building on the Essential Question When would I choose to decompose a multiplication fact rather than draw a picture? Answer: Decompose the multiplication fact is decompose the one of the factor to double the unknown fact. Example is 4 x 6 = 24. Decompose 6 into 3 + 3. 4 x 3 = 12. 4 x 3 = 12. The picture is ### McGraw Hill My Math Grade 3 Chapter 8 Lesson 4 My Homework Answer Key Practice Double a known fact to find each product. Question 1. 5 × 8 = ____ 5 × ___ = ___ 5 × ___ = ___ ____ + ____ = ____ Answer: Multiplication of 5 with 8 then you get 40. 5 x 8 = 40. Convert 8 with 4 + 4. 5 x 4 = 20. 5 x 4 = 20. The known fact is 20. Double the product is 20 + 20 = 40. Question 2. 4 × 8 = ____ 4 × ___ = ___ 4 × ___ = ___ ____ + ____ = ____ Answer: Multiplication of 4 with 8 then you get 32. 4 x 8 = 32. Convert 8 into 4 + 4. 4 x 4 = 16. 4 x 4 = 16. The known fact is 16. Double the product is 16 + 16 = 32. Algebra Find each unknown. Use the Commutative Property. Question 3. 8 × = 40 × 8 = 40 The unknown is ___. Answer: Multiplication of 8 with 5 then you get 40. 8 x 5 = 40. 5 x 8 = 40. The unknown is 5. Question 4. × 8 = 56 8 × = 56 The unknown is ___. Answer: Multiplication of 7 with 8 then you get 56. 7 x 8 = 56. 8 x 7 = 56. The unknown is 7. Question 5. 2 × 8 = 8 × 2 = The unknown is ___. Answer: Multiplication of 2 with 8 then you get 16. 2 x 8 = 16. Multiplication of 8 with 2 then you get 16. 8 x 2 = 16. The unknown is 16. Question 6. 8 × = 64 × 8 = 64 The unknown is ___. Answer: Multiplication of 8 with 8 then you get 64. 8 x 8 = 64. 8 x 8 = 64. The unknown is 8. Multiply. Question 7. Answer: Multiplication of 1 with 8 then you get 8. 1 x 8 = 8. Question 8. Answer: Multiplication of 8 with 9 then you get 72. 8 x 9 = 72. Question 9. Answer: Multiplication of 8 with 0 then you get 0. 8 x 0 = 0. Question 10. Answer: Multiplication of 3 with 8 then you get 24. 3 x 8 = 24. Problem Solving Mathematical PRACTICE 2 Use Symbols Write a multiplication sentence with a symbol for the unknown. Then solve. Question 11. There were 5 dolphins swimming around a tour boat. Each dolphin circled the boat 8 times. What is the total number of times all of the dolphins circled the boat? Answer: Given that, There are 5 dolphins swimming around a tour boat. Each dolphin circled the boat 8 times. So, 5 x 8 = 40. Therefore the total number of times all of the dolphins circled the boat is 40. Question 12. Cameron worked 8 hours at the coffee shop. He earned the same amount in tips each hour. At the end of his shift, Cameron had$32 in tips. How much money did he earn in tips each hour?
Given that,
Cameron worked 8 hours at the coffee shop.
He earned the same amount in tips each hour.
Cameron had $32 in tips. So,$32/8 = $4. Therefore Cameron earn in tips for each hour is$4.

Test Practice

Question 13.
Stuart knows spiders have 8 legs. Which shows a known fact Stuart can double to find the number of legs on 7 spiders?
A. 4 × 3 = 12
B. 4 × 7 = 28
C. 4 × 8 = 32
D. 7 × 8 = 56