Practice the questions of **McGraw Hill Math Grade 4 Answer Key** **PDF Chapter 5 Lesson 5 Using Mental Math to Multiply** to secure good marks & knowledge in the exams.

## McGraw-Hill Math Grade 4 Answer Key Chapter 5 Lesson 5 Using Mental Math to Multiply

**Multiply**

**Find each product using mental math.**

Question 1.

10 × 300 = __300
__Explanation:

1 x 3 = 3

The number of zeros in the product is same as the number of zeros in the factors

If the product ends with zero then add the zeros to the result

Question 2.

40 × 90 = ____

Answer:

4 x 9 = 36

so, 3600

40 x 90 = 3600

Explanation:

The number of zeros in the product is same as the number of zeros in the factors

If the product ends with zero then add the zeros to the result

Question 3.

400 × 30 = ___

Answer:

4 x 3 = 12

so, 400 x 30 = 12000

Explanation:

The number of zeros in the product is same as the number of zeros in the factors

If the product ends with zero then add the zeros to the result

Question 4.

800 × 70 = ___

Answer:

8 x 7 = 56

so, 800 x 70 = 56000

Explanation:

The number of zeros in the product is same as the number of zeros in the factors

If the product ends with zero then add the zeros to the result

Question 5.

500 × 40 = ___

Answer:

5 x 4 = 20

so, 500 x 20 = 20000

Explanation:

The number of zeros in the product is same as the number of zeros in the factors

If the product ends with zero then add the zeros to the result

Question 6.

25 × 600 = ___

Answer:

25 x 6 = 150

so, 25 x 600 = 15000

Explanation:

The number of zeros in the product is same as the number of zeros in the factors

If the product ends with zero then add the zeros to the result

Question 7.

40 has one zero. 500 has two zeros. Why does the product of 40 and 500 have four zeros? Explain.

Answer:

as 4 x 5 = 20

The product zero is also added.

Explanation:

The number of zeros in the product is same as the number of zeros in the factors

If the product ends with zero then add the zeros to the result