Division

Using multiplication and repeated subtraction

What’s It All About?

You are going to learn:

How to divide by inversing multiplication and using repeated subtraction.

What skills should you have already?

You need to be able to multiply and subtract two values using a written method.

Remember that 6 ÷ 3 means “how many threes make 6?”

Division is the INVERSE of Multiplication.

There are different ways of showing division.

6 ÷ 3

The answer is the same in all three cases!

63

3 6

Division

For multiplying, we can use a grid like this:

We can now use it to divide as well as multiply.

Example: 20 4 means “How many 4’s make 20?”

Using Multiplying to Divide

1 2 3 4 5 6 7 8 9

2 2 4 6 8 10 12 14 16 18

3 3 6 9 12 15 18 21 24 27

4 4 8 12 16 20 24 28 32 36

5 5 10 15 20 25 30 35 40 45

6 6 12 18 24 30 36 42 48 54

The answer is 5.

Remember that 6 ÷ 3 means “how many threes make 6?”

Work out:

1. 16 ÷ 4

2. 30 ÷ 5

3. 30 ÷ 10

4. 45 ÷ 9

5. 72 ÷ 8

6. 21 ÷ 3

7. 21 ÷ 7

Your Turn

Work out £192 ÷ 6Set up the method:

Multiply 6 by something easy such as 10 or 100, then subtract.

Repeat this until you have nothing left or the number that is left is less than 6.

Stop. Total up the 6’s.

10

Repeated Subtraction 1

232

120

6 19260

1321060

106072

12

£192 6 = 32

Work out £324 ÷ 12Set up the method:

Multiply 12 by something easy such as 10 or 100, then subtract.

Repeat this until you have nothing left or the number that is left is less than 12.

Stop. Total up the 12’s.

10

Repeated Subtraction 2

227

240

12 324120204

10120

56084

24

£324 12 = 27

Work out £3010 ÷ 14Set up the method:

Multiply 14 by something easy such as 10 or 100, then subtract.

Repeat this until you have nothing left or the number that is left is less than 14.

Stop. Total up the 14’s.

100

Repeated Subtraction 3

5215

700

14 301014001610

1001400

10140210

70

£3010 14 = 215

Choosing sensible numbers reduces the amount of

subtracting you have to do ....

Remember that 6 ÷ 3 means “how many threes make 6?”

Work out:

1. 164 ÷ 4

2. 305 ÷ 5

3. 3040 ÷ 10

4. 4509 ÷ 9

Your Turn

5. 156 ÷ 12

6. 315 ÷ 15

7. 3040 ÷ 20

8. 2814 ÷ 14

End