This activity is about keeping pairs of numbers in the same **ratio**.

If two quantities are in **direct proportion**, the ratio between corresponding values will always be the same.

a | = | 1 | 2 | 3 | 4 | 5 |

b | = | 1.5 | 3 | 4.5 | 6 | 7.5 |

In this table the ratio between **a** and **b **can be found by **dividing** the value of **b** by its corresponding value of **a.**

Where B is 3 and A is 2: ** 3 ÷ 2 = 1.5**

Where B is 4.5 and A is 3: ** 4.5 ÷ 3 = 1.5**

Now we know that the** ratio between a and b is 1.5**

If we know a and we want to find b, we simply **multiply a by 1.5**

For example, if a = 6 then b = 1.5 × 6 = 9

We can also use this **ratio** to find the value of** a** if we know what **b** is. We do the inverse and simply** divide b by 1.5**

For example if b = 15, then a = 15 ÷ 1.5 = 10

The best way to check that we've got this is to try some questions, so let's get started.