#### Solved Examples and Worksheet for Multiplying Number or Decimal with Powers of 10

Q1Find the product of 309 and 0.01.

A. 2.54
B. 3.09
C. 4.32
D. 3.64

Step: 1
0.01 × 309
[Original expression.]
Step: 2
 0.01 [Two decimal.] × 309 [No decimal.] 3.09 [Two decimal.]
Q2Cost of each toy is $7.39. Andy bought 10 toys. How much did he spend on toys? A.$73900
B. $73.90 C.$739
D. $7,390 Step: 1 To find the amount that Andy spent on 10 toys, we have to multiply cost of each toy by 10. Step: 2 Cost of each toy =$7.39
Step: 3
Amount that Andy spent on 10 toys = $7.39 × 10 =$73.90.
[To multiply a decimal by 10, move the decimal point one place to the right.]
Correct Answer is :   $73.90 Q3Cost of each book is$10.50. Jerald bought 10 books. How much did he spend on books?

A. $105.00 B.$10500
C. $1.050 D.$1050

Step: 1
To find the amount that Jerald spent on 10 books, we have to multiply cost of each book by 10.
Step: 2
Cost of each book = $10.50 Step: 3 Amount that Jerald spent on 10 books =$10.50 × 10 = $105.00 [To multiply a decimal by 10, move the decimal point one place to the right.] Correct Answer is :$105.00
Q4Which of the following is the next multiplication sentence?
25 × 10
25 × 100
25 × 1000

A. 25 × 10000
B. 25 × 1000
C. 250 × 10000

Step: 1
In the pattern the number 25 is constant but the second number 10 is increasing 10 times in every subsequent product. In the last term, its value is 1000.
Step: 2
So, 1000 × 10 = 10,000.
Step: 3
The next multiplication sentence in the given pattern is 25 × 10000.
Correct Answer is :   25 × 10000
Q5Which two are the missing numbers?
80 × 10 = ___

4 × ___ = 40

A. 80 and 100
B. 800 and 10
C. 8000 and 10

Step: 1
80 × 10 = 800 and 4 × 10 = 40
Step: 2
So, the missing numbers are 800 and 10.
Correct Answer is :   800 and 10
Q6Which pair of numbers best completes the equation?

A. Pair 3
B. Pair 1
C. Pair 2

Step: 1
Among the choices, 58 × 10 = 580
Step: 2
So, Pair 3 best completes the equation.
Correct Answer is :   Pair 3
Q7Identify the pair of numbers that best completes the equation.

A. Pair 2
B. Pair 1
C. Pair 3

Step: 1
Among the choices, 76 × 100 = 7,600.
Step: 2
So, Pair 3 best completes the equation.
Correct Answer is :   Pair 3
Q8Find the product of 63 and 1 000.

A. 83,000
B. 63,000
C. 63,010
D. 6,300

Step: 1
The product of 63 and 1,000 is 63 × 1,000 or 1,000 × 63.
Step: 2

Step: 3
So, the product of 63 and 1,000 is 63,000.
Q9Find the value of 54 × 1,000.
A. 5,400
B. 54,000
C. 54,400
D. 54,010

Step: 1

Step: 2
So, the value of 54 × 1,000 is 54,000.
Q10Multiply:
25 × 1,000 =

A. 25,010
B. 2,505
C. 2,500
D. 25,000

Step: 1

Step: 2
So, 25 × 1,000 = 25,000.
Q11Multiply:
1.23 × 10 =

A. 12.20
B. 11.30
C. 11.20
D. 12.30

Step: 1
 2 3 1 . 2 3 × 10 1 2 . 3 0
Step: 2
1.23 × 10 = 12.30
Q122.525 × 1 000 =

A. 252.5
B. 25.25
C. 2 525
D. 25 250

Step: 1
 2 . 5 2 5 × 1 0 0 0 2 5 2 5 . 0 0 0
Step: 2
2.525 × 1 000 = 2 525
Correct Answer is :   2 525
Q13Which of the following is equivalent to 27.006 × 100?

A. 270.06
B. 2.7006
C. 2 700.6
D. 2 7006

Step: 1
To multiply a decimal by 100, move the decimal point two places to the right.
Step: 2
27.006 × 100 = 2 700.6
Correct Answer is :   2 700.6
Q14Multiply:
115 × 100

A. 1,150
B. 1,500
C. 11,500
D. 1,15,000

Step: 1

Step: 2
So, 115 × 100 = 11,500
Q15There are 100 rows in a rose plants garden. Each row has 22 roses. Find the number of roses in the garden.
A. 2000
B. 2100
C. 2200
D. 2500

Step: 1
Number of rows in the garden = 100.
Step: 2
Number of roses in each row = 22.
Step: 3
Number of roses in the garden = (number of rows) × (number of roses in each row)
Step: 4
= 100 × 22
Step: 5
= 2200
Step: 6
So, number of roses in the garden = 2200.