Multiply / Divide decimals by 10, 100, 1000. Interactive worksheet ... - Free Printable

Let's solve the problems step by step based on the rules provided in the worksheet:

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Part 1: Multiplying and Dividing with Decimals

#### Multiplying with Decimals
- Rule: Move the decimal point to the right by the number of zeros in the multiplier (10, 100, 1000).
- Example:
$ 87.6 \times 100 = 8,760 $ → move decimal 2 places right.

#### Dividing with Decimals
- Rule: Move the decimal point to the left by the number of zeros in the divisor.
- Example:
$ 87.6 \div 100 = 0.876 $ → move decimal 2 places left.

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Section A: Multiply and Divide

#### Multiplication (Left Side):

a) $ 43 \times 10 = ? $
→ Move decimal 1 place right:
$ 43.0 \rightarrow 430 $
✔ Answer: 430

b) $ 789 \times 100 = ? $
→ Move decimal 2 places right:
$ 789.0 \rightarrow 78,900 $
✔ Answer: 78,900

c) $ 3.5 \times 100 = ? $
→ Move decimal 2 places right:
$ 3.5 \rightarrow 350 $
✔ Answer: 350

d) $ 58.3 \times 10 = ? $
→ Move decimal 1 place right:
$ 58.3 \rightarrow 583 $
✔ Answer: 583

e) $ 0.324 \times 1000 = ? $
→ Move decimal 3 places right:
$ 0.324 \rightarrow 324 $
✔ Answer: 324

f) $ 2.098 \times 100 = ? $
→ Move decimal 2 places right:
$ 2.098 \rightarrow 209.8 $
✔ Answer: 209.8

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#### Division (Right Side):

a) $ 39 \div 10 = ? $
→ Move decimal 1 place left:
$ 39.0 \rightarrow 3.9 $
✔ Answer: 3.9

b) $ 410 \div 100 = ? $
→ Move decimal 2 places left:
$ 410.0 \rightarrow 4.10 $
✔ Answer: 4.1

c) $ 654 \div 1000 = ? $
→ Move decimal 3 places left:
$ 654.0 \rightarrow 0.654 $
✔ Answer: 0.654

d) $ 8.3 \div 10 = ? $
→ Move decimal 1 place left:
$ 8.3 \rightarrow 0.83 $
✔ Answer: 0.83

e) $ 342.5 \div 100 = ? $
→ Move decimal 2 places left:
$ 342.5 \rightarrow 3.425 $
✔ Answer: 3.425

f) $ 0.23 \div 100 = ? $
→ Move decimal 2 places left:
$ 0.23 \rightarrow 0.0023 $
✔ Answer: 0.0023

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Section B: Fill in the Blanks

We now need to find the missing number (either multiplier or divisor).

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a) $ 73 \times \_\_\_\_\_\_ = 7300 $
→ We know $ 73 \times 100 = 7300 $
✔ Answer: 100

b) $ 873 \div \_\_\_\_\_\_ = 87.3 $
→ 873 ÷ 10 = 87.3
✔ Answer: 10

c) $ 0.802 \times 100 = ? $
→ $ 0.802 \times 100 = 80.2 $
✔ Answer: 80.2

d) $ \_\_\_\_\_\_ \div 1000 = 42.09 $
→ To get back: $ 42.09 \times 1000 = 42,090 $
✔ Answer: 42,090

e) $ 9.231 \times \_\_\_\_\_\_ = 923.1 $
→ 9.231 × 100 = 923.1
✔ Answer: 100

f) $ 98.02 \times \_\_\_\_\_\_ = 98020 $
→ 98.02 × 1000 = 98,020
✔ Answer: 1000

g) $ 9.002 \div \_\_\_\_\_\_ = 0.09002 $
→ 9.002 ÷ 100 = 0.09002
✔ Answer: 100

h) $ 2.0901 \times \_\_\_\_\_\_ = 2090.1 $
→ 2.0901 × 1000 = 2090.1
✔ Answer: 1000

i) $ 0.124 \div \_\_\_\_\_\_ = 0.00124 $
→ 0.124 ÷ 100 = 0.00124
✔ Answer: 100

j) $ 18.9802 \div \_\_\_\_\_\_ = 1.89802 $
→ 18.9802 ÷ 10 = 1.89802
✔ Answer: 10

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✔ Final Answers:

#### Section A:

Multiplication:
a) 430
b) 78,900
c) 350
d) 583
e) 324
f) 209.8

Division:
a) 3.9
b) 4.1
c) 0.654
d) 0.83
e) 3.425
f) 0.0023

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#### Section B:

a) 100
b) 10
c) 80.2
d) 42,090
e) 100
f) 1000
g) 100
h) 1000
i) 100
j) 10

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📝 Summary:

- When multiplying by 10, 100, 1000 → move decimal right.
- When dividing by 10, 100, 1000 → move decimal left.
- Number of decimal places moved = number of zeros in the power of 10.

This method makes multiplying and dividing decimals quick and easy!