Very simply, a ratio tells us how much of one thing there is compared to another thing. If a fruit bowl has 4 apples and 6 oranges the ratio of apples to oranges is 4 to 6, written,

4 : 6 like this, with a colon.

Numerical tests will sometimes ask you to simplify a ratio, they might ask:

My business has 34,280 employees based in London and 14,342 employees based in Paris. What is the simplified ratio of employees based in Paris to London?

First we translate the question into a ratio format. 14,342 : 34,280

Notice that the question asks for the employee ratio of Paris to London, meaning Paris comes first when we note the number of employees, so we write: 14,342 to 34,280.

Next, we divide both sides of the ratio by the smallest number, here that’s 14,342:

14,342 divided by 14,342 equals 1 34,280 divided by 14:342 equals 2.39

Which leaves us with

1 : 2.39 - a simplified ratio