You will come across fractions in everyday life - half a pint of milk, quarter of an ounce of butter, an eighth of a pizza etc. Fractions are everywhere so you won't be surprised to find them in KS3 Maths.

Multiplying fractions is relatively easy. All you have to do is change any mixed numbers to top heavy fractions, then multiply the top row, and multiply the bottom row. So, to multiply 1^{1}⁄_{4} x ^{2}⁄_{5} first change 1^{1}⁄_{4} to ^{5}⁄_{4}. Next multiply 5 x 2 and 4 x 5 to get ^{10}⁄_{20}. Always look to see if you can cancel down: ^{10}⁄_{20} is the same as ^{1}⁄_{2}.

Dividing fractions is similar to multiplying, except you invert the second fraction, and change the divide sign to multiply. So, 1^{1}⁄_{4} ÷ ^{2}⁄_{5} would be ^{5}⁄_{4} x ^{5}⁄_{2}. 5 x 5 = 25 and 4 x 2 = 8 so your answer is ^{25}⁄_{8} or
3^{1}⁄_{8}.

Have a read of our Helping Children Learn Fractions page. It explains how fractions work and gives handy tips.

1.

What is 1/9 x 3/5?

1/12

1/14

1/15

1/18

1 x 3 = 3 and 9 x 5 = 45 so we get the answer 3/45 or 1/15

2.

What is 2^{1}⁄_{4} x 2^{1}⁄_{5}?

2^{3}⁄_{10}

3^{5}⁄_{10}

4^{19}⁄_{20}

5^{1}⁄_{2}

2^{1}⁄_{4} becomes ^{9}⁄_{4} which we multiply by 2^{1}⁄_{5} or ^{11}⁄_{5} to get ^{99}⁄_{20} or 4^{19}⁄_{20}

3.

A piece of copper wire is 7^{2}⁄_{3}m long. What is the total length of three of these wires?

22^{3}⁄_{8}

23

24^{1}⁄_{3}

26

3 x 7 = 21 and 3 x 2/3 = 6/3 or 2 then add these two numbers together

4.

What is 3/8 of £48.00?

£6.00

£10.00

£14.00

£18.00

Rewrite the question as 3/8 x 48. 48 / 8 = 6, 6 x 3 = 18, therefore the answer is £18.00

5.

What is ^{3}⁄_{10} ÷ ^{6}⁄_{25}?

1

1^{1}⁄_{4}

1^{1}⁄_{2}

1^{3}⁄_{4}

To divide by a fraction, invert and multiply: 3/10 ÷ 6/25 = 3/10 x 25/6. Use this method whenever you have to divide by fractions

6.

Daniel is making pancakes. Each pancake uses ^{1}⁄_{8} of a litre of batter. How much batter is used if Daniel makes 20 pancakes?

2^{1}⁄_{2} litres

2^{3}⁄_{4} litres

3^{1}⁄_{3} litres

4^{1}⁄_{3} litres

I'll have lemon and sugar on mine please!

7.

What is 2^{3}⁄_{4} ÷ 4^{1}⁄_{8}?

1/3

1/2

2/3

3/4

Remember to invert the second fraction and change the divide sign to multiply

8.

14,000 fans attended the football match yesterday. 6/7 of them wore scarves. How many were without scarves?

2,000

4,000

8,000

10,000

6/7 of 14,000 = 12,000, therefore 2,000 were without scarves

9.

In a jar of 120 sweets, one in every six sweets is orange flavoured. If half the orange sweets are eaten, what fraction of the sweets is left?

10.

What is ^{9}⁄_{14} ÷ 1^{1}⁄_{2}?

1/7

2/7

3/7

5/7

To divide by a fraction, invert and multiply