In Year 5, the third year in KS2, children will be shown how to compare numbers in the form of a ratio in Maths. This is a simple concept which allows them to visualise a comparison between two quantities.

You may have seen numbers placed either side of a colon before, perhaps something like this - 2:1 or 3:1, but what do the numbers mean? Well, we call these ratios. A ratio is the comparison of two numbers or quantities. For example, in a bowl of fruit there are 8 apples and 6 pears. The ratio of apples to pears would be 8:6 (or 4:3 which is equivalent to 8:6). Do you know what the ratio is of pears to apples? Well, we just turn the numbers around. The ratio of pears to apples is 6:8 (or 3:4). Ratios are a great tool which can help us to understand how different amounts compare to one another.

How much do you know about using ratio for the comparison of different quantities? Find out in our quiz.

1.

There are 3 yellow boxes for every 1 blue box. If there are 6 yellow boxes how many blue boxes are there?

2

3

6

12

If there are 6 yellow boxes then that is twice the number given in the ratio. Therefore we must multiply the number of blue boxes by 2

2.

In every 10 bricks, 3 are red. We have 30 bricks so how many are red?

3

6

9

15

The number of bricks has been multiplied by 3 so the number of red bricks needs to be multiplied by 3

3.

The ratio between blue boxes and yellow boxes is 3:2. If there are 4 yellow boxes how many blue boxes are there?

2

3

6

10

The amount of yellow boxes has been multiplied by 2 so we must multiply the blue boxes by 2

4.

When making a cake, for every 400g of flour 200g of sugar is required. What is another way of saying this?

We require half as much flour as sugar

We require twice more sugar than flour

We require the same amount of sugar and flour

We require half as much sugar as flour

The ratio between flour and sugar is 2:1

5.

If there is a 5:2 ratio between black squares and white squares which number represents the white squares?

1

2

5

10

The 2 represents the white squares while the 5 represents the black squares as black was mentioned first

6.

For every 2 black squares there is 1 white square. What is the ratio of black to white?

2:1

1:2

3:2

1:1

It there is a ratio of 2:1 then there is twice as much of the first thing than the last

7.

John has twice as many stamps than Yasif. If Yasif has 5 stamps how many stamps does John have?

5

10

15

20

The ratio between John and Yashif's stamps is 2:1

8.

Zara uses 20ml of fruit concentrate for every 60ml of water. How much fruit concentrate will she require for 180ml of water?

20ml

40ml

50ml

60ml

The amount of water has increased 3 times so the same must happen to the amount of fruit concentrate

9.

Chicken should be cooked for 50 minutes for every kg. How long will it take to cook a 3kg chicken?

100 minutes

150 minutes

175 minutes

200 minutes

Or two and a half hours

10.

Lucy mixes 4 small pots of white paint with 1 small pot of red paint to make 1 large tin of pink paint. She requires 5 large tins of pink paint. How many small pots of white paint does she need?

5 tins

10 tins

20 tins

30 tins

There are 4 pots of white paint in each tin of pink, so 5 tins of pink means 4 x 5 = 20