Explain how to multiply and divide a number by 10, 100 and 1,000 | Maths

Starter quiz

Look at the Gattegno chart. Which number is being represented?

'4.3' ✓
Match the expressions to their product.

9 × 100 =

⇔

900 ✓

9 × 10 =

⇔

90 ✓

9 × 1 =

⇔

9 ✓

2 × 10 =

⇔

20 ✓

2 × 100 =

⇔

200 ✓

2 × 0 =

⇔

0 ✓
When a number is multiplied by one hundred, the digits are moved __________ place value places to the left.

one

two ✓

three

four
Match the equations to their product.

7 × 1,000 =

⇔

7,000 ✓

7000 ÷ 1,000 =

⇔

7 ✓

5,000 × 0.001 =

⇔

5 ✓

5,000 × 0.1 =

⇔

500 ✓

5,000 ÷ 100 =

⇔

50 ✓

3,000 × 0.01 =

⇔

30 ✓
Sofia is thinking of a number. Her number is ten times the size of 0.4 What is her number?

0.04

0.4

4 ✓

40

400
Lucas is thinking of a number. His number is one hundredth times the size of 8 What is his number?

0.008

0.08 ✓

0.8

80

800

Exit quiz

When we multiply 0.95 by 100, what is the new value of the 9 digit?

Nine hundredths

Nine tenths

Nine ones

Nine tens ✓

Nine hundreds
1.04 × 10 = ______

1.040

14

10.4 ✓

104
0.03 ÷ 10 = ______.

0.3

.003

0.003 ✓

.3

0.03
Match the expression to its product.

0.72 × 10

⇔

7.2 ✓

0.72 × 1,000

⇔

720 ✓

4.82 × 10

⇔

48.2 ✓

4.82 × 100

⇔

482 ✓

0.91 × 10

⇔

9.1 ✓

0.91 × 100

⇔

91 ✓
Sofia buys an apple every day. If one apple costs £0.35, how much has she spent after 10 days?

'£3.50' ✓
Lucas’ mum has £5,042 and she gives one-hundredth of this to Lucas for his birthday. How much money does she give him?

'£50.42' ✓

Worksheet

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Lesson Details

Key learning points

When you multiply by 10, 100 or 1,000, the digits move one, two or three places to the left respectively.
When you divide by 10, 100 or 1,000, the digits move one, two or three places to the right respectively.

Common misconception

Children may 'add' a zero when multiplying or vice versa when dividing. Children may place a zero at the end of the decimal fraction when multiplying, or vice versa when dividing.

When we 'add' zero, the value of the number does not change. When we multiply or divide by a power of 10, we need to move all the digits the appropriate spaces to the left/right even if this means bridging one and moving into the decimal places.

Keywords

Tenth - One-tenth is one part in ten equal parts.
Hundredth - One-hundredth is one part in one hundred equal parts.
Thousandth - One-thousandth is one part in one thousand equal parts.