Ratio and proportion

What you'll learn

1. 1

   Imagine you're making orange squash. For every 1 part of squash, you add 4 parts of water. That's a ratio of 1:4!

2. 2

   If the ratio of squash to water is 1:4, how much water do you add for 1 part of squash?

3. 3

   Use the bar model to show 1 part squash and 4 parts water. How many parts are there in total?

4. 4

   Let's work out: If the ratio of boys to girls in a class is 2:3 and there are 10 boys, how many girls are there?

5. 5

   Now try this: The ratio of red to blue marbles is 3:5. There are 12 red marbles. How many blue marbles are there? Use the bar model to help.

6. 6

   The ratio of cats to dogs is 1:2. If there are 7 cats, how many dogs are there?

7. 7

   A recipe uses a ratio of flour to sugar of 3:1. If you use 9 cups of flour, how much sugar do you need?