Home learning focus
Today you will find out what ratios are, how ratios are written and how to convert between a ratio and a fraction.
This lesson includes:
- one videos
- three interactive activities
What is a ratio?
A ratio shows how much of one thing there is compared to another. Ratios are usually written in the form a:b.
If you are making orange squash and you mix one part orange to four parts water, then the ratio of orange to water will be 1:4 (1 to 4).
The order in which a ratio is stated is important. Changing the order of the numbers in a ratio changes the proportions and would mean the orange squash was very strong!
Ratios as fractions
Ratios can be used to show fractions and proportions of amounts. Proportion is used to show how quantities and amounts are related to each other.
A room has to be painted blue and yellow in the ratio 2:3. Express the proportion of the room that has to be painted in each colour as a fraction.
There are five parts in this ratio: 2 blue + 3 yellow = 5 total
The fraction painted blue is ⅖ and the fraction painted yellow is ⅗.
There's more to learn
Have a look at these other resources around the BBC and the web.