Ratio · Year 6
In Year 6 you learn: comparing quantities with ratio.
A ratio compares the sizes of two or more quantities: 3 : 5 means “for every 3 of the first there are 5 of the second”. Ratios are used in recipes, maps, mixing paint and sharing money fairly.
Key facts
- In the ratio a : b, the first quantity is a/(a + b) of the total.
- A map scale of 1 : 25,000 means 1 cm on the map is 25,000 cm (250 m) in real life.
Worked examples
Example 1
Write 45 : 60 in its simplest form.
Answer: 3 : 4
Example 2
The ratio of boys to girls in a club is 4 : 7. There are 28 girls. How many children are in the club?
Answer: 44