This activity is about finding percentage change.

Example 1

A metal bar increases its length from 2 m to 2.01 m after heating.

Find the percentage increase in its length.

Actual increase = 2.01 - 2 = 0.01 m

Percentage increase = (actual increase ÷ original length) x 100 = (0.01 ÷ 2) x 100 = 0.5%

Example 2

A woman reduced her weight from 80 kg to 63 kg after dieting.

Find the percentage decrease in her weight.

Actual decrease = 80 - 63 = 17 kg.

Percentage decrease = (actual decrease ÷ original weight) x 100 = (17 ÷ 80) x 100 = 21.25

Just remember the formula for percentage change = (actual change ÷ original) x 100 

Let's try some questions now.