Calculate Simple Ratios

In this activity, we will learn about simple ratios.

1 in every 4 beads is green.

Examples

Complete each sentence so that the beads stay in the same ratio.

2 in every 8 are green...........this is what we get in 2 groups of 4 beads

3 in every 12 are green...........this is what we get in 3 groups of 4 beads

7 in every 28 are green...........this is what we get in 7 groups of 4 beads

20 in every 80 are green...........this is what we get in 20 groups of 4 beads

It helps to know how many groups of 4 beads there are.

Example

If there are 12 green beads, how many beads are not green?

Answer

36

To work this question out, we can use multiplication facts:

The ratio is 3:1 (white:green)

If 12 beads are green, 1 x 12 = 12, so we do 3 x 12 = 36 to get the number of white beads.

Let's have a go at some questions now.