Go through the Math in Focus Grade 5 Workbook Answer Key Chapter 2 Practice 3 Multiplying by Powers of Ten to finish your assignments.

## Math in Focus Grade 5 Chapter 2 Practice 3 Answer Key Multiplying by Powers of Ten

Example

36 × 10^{2} = 36 × (__10__ × __10__)

= 36 × __100__

= __3,600__

Question 1.

17 × 10^{2} = 17 × (_10__ × _10__)

= 17 × _100__

= __1,700___

Answer:

1,700,

Explanation:

Given to find 17 X 10^{2} so multiplying powers of 10 as

17 X 10 X 10 we get 17 X 100 = 1,700.

Question 2.

98 × 10^{2} = 98 × (_10__ × _10__)

= 98 × _100_

= __9,800___

Answer:

9,800,

Explanation:

Given to find 98 X 10^{2} so multiplying powers of 10 as

98 X 10 X 10 we get 98 X 100 = 9,800.

Question 3.

432 × 10^{2} = 432 × (_10__ × _10__)

= 432 × _100__

= __43,200___

Answer:

43,200,

Explanation:

Given to find 432 X 10^{2} so multiplying powers of 10 as

432 X 10 X 10 we get 432 X 100 = 43,200.

**Multiply.**

Question 4.

625 × 10^{2} = _625__X (10 X 10) = 62,500

Answer:

62,500,

Explanation:

Given to find 625 X 10^{2} so multiplying powers of 10 as 2 times 10 we get

625 X 10 X 10 = 625 X 100 = 62,500.

Question 5.

1,000 × 10^{2} = __1,00,000_

Answer:

1,00,000,

Explanation:

Given to find 1,000 X 10^{2} so multiplying powers of 10 as 2 times 10 we get

1,000 X 10 X 10 = 1,000 X 100 = 1,00,000.

Question 6.

5,118 × 10^{2} = _5,11,800__

Answer:

5,11,800,

Explanation:

Given to find 5,118 X 10^{2} so multiplying powers of 10 as 2 times 10 we get

5,118 X 10 X 10 = 5,118 X 100 = 5,11,800.

Question 7.

Tyler multiplied 3,406 × 10^{2} in the following way:

3,406 × 10^{2} = 3,406 × 10 × 2

= 34,060 × 2

= 68,120

Is Tyler’s method correct? If not, explain the error and show the correct way to

evaluate the numerical expression. Multiply.

Answer:

Wrong, Correct evaluation is 3,40,600,

Explanation:

Given Tyler multiplied 3,406 × 10^{2} in the following way:

3,406 × 10^{2},

= 3,406 × 10 × 2,

= 34,060 × 2,

= 68,120, Tyler’s method is incorrect the error is that instead of multiplying powers of

10 as 2 times 10 by using numerical expression 10 X 10,

Tyler multiplyed 10 with 2.

So by evaluating we get 3,406 X 10^{2} = 3,406 X 10 X 10,

= 3,406 X 100 =3,40,600.

**Multiply.**

Example

62 × 10^{3} = 62 × (__10__ × __10__ × __10__)

= 62 × __1000__

= __62,000__

Question 8.

53 × 10^{3} = 53 × ( _10_ × _10__ × _10_)

= 53 × _1,000__

= _53,000__

Answer:

53,000,

Explanation:

Given to find 53 X 10^{3} so multiplying powers of 10 as 3 times 10 ,

we get 53 X 10 X 10 X 10 = 53,000,

Question 9.

74 × 10^{3} = 74 × (_10_ × _10_ × _10_)

= 74 × _1,000__

= _74,000__

Answer:

74,000,

Explanation:

Given to find 74 X 10^{3} so multiplying powers of 10 as 3 times 10,

we get 74 X 10 X 10 X 10 = 74,000.

Question 10.

318 × 10^{3} = 318 × (_10_ × _10_ × _10__)

= 318 × _1,000__

= __3,18,000_

Answer:

3,18,000,

Explanation:

Given to find 318 X 10^{3} so multiplying powers of 10 as 3 times 10,

we get 318 X 10 X 10 X 10 = 3,18,000.

**Multiply.**

Question 11.

907 × 10^{3} = __907_ X ( 10 X 10 X 10) = 9,07,000

Answer:

9,07,000,

Explanation:

Given to find 907 X 10^{3} so multiplying powers of 10 as 3 times 10,

we get 907 X 10 X 10 X 10 = 3,18,000.

Question 12.

4,125 × 10^{3} = _4,125__ X 10 X 10 X 10 = 41,25,000

Answer:

41,25,000,

Question 13.

2,000 × 10^{3} = _2,000__ X 10 X 10 X 10 = 20,00,000

Answer:

20,00,000,

Explanation:

Given to find 2,000 X 10^{3} so multiplying powers of 10 as 3 times 10,

we get 2,000 X 10 X 10 X 10 = 20,00,000.

**Complete with 10,10 ^{2}, or 10^{3}.**

Question 14.

To change from kilograms to grams, multiply by _0.001__

Answer:

0.001,

Explanation:

Changing from kilograms to grams as 1 gram is equal to 1000 kilograms,

we divide kilogram by gram which is equal to 1 ÷ 10^{3} = 1 ÷ 1,000 = 1 ÷ 0.001.

**Math Journal**

Jodi estimated these products.

a. 2,892 × 21 rounds to 3,000 × 20 = 60,000

Answer:

60,000,

Explanation:

Given to multiply 2,892 by 21 so rounding 2,892 to

3,000 and 21 to 20 we get 3,000 X 20 = 60,000.

b. 2,743 × 18 rounds to 3,000 × 20 = 60,000

Answer:

60,000,

Explanation:

Given to multiply 2,743 by 18 so rounding 2,892 to

3,000 and 21 to 20 we get 3,000 X 20 = 60,000.

She then worked out the actual answers. Even though the estimated answers were the same,

Jodi found that the actual answers were very different from each other.

Question 1.

In which case is the estimate closer to the actual answer? Explain why.

Answer:

In the estimate a Jodi is closer to the actual answer,

Explanation:

In the estimation a Jodi is closer to the actual answer,

why because while working out with the answers even though

the estimated answers were the same Jodi found that the actual answers

are differing why because while rounding the estimates the closer value

is method (a) as 2,892 has greater value than 2,743.

Question 2.

If an estimate does not make your answer seem reasonable,

what can you do to make sure you have done your work correctly?

Answer:

By evaluting the values and making it sure that I have done my work correctly,

Explanation:

By evaluting the values and making it sure that I have done my work correctly as

method (a) as 2,892 has greater value than 2,743.