½ = = 50%
⅖ = = 40%
¾ = = 75%
Jamal earns £1200 for a job he does and pays his agent £150 in commission.
Express his agent’s commission as a percentage of Jamal’s earnings.
(a) Increase £200 by 18%
Write 18% as a percentage (by dividing by 100)
18 ÷ 100 = 0.18
Find the decimal equivalent of an 18% increase (by adding 1 to 0.18)
1 + 0.18 = 1.18
Multiply £200 by 1.18
200 × 1.18
£236
(b) Decrease 500 kg by 23%
Write 23% as a percentage (by dividing by 100)
23 ÷ 100 = 0.23
Find the decimal equivalent of a 23% decrease (by subtracting 0.23 from 1)
1 – 0.23 = 0.77
Multiply 500 by 0.77
500 × 0.77
385 kg
(c) The number of students in a school goes from 250 to 310. Describe this as a percentage change.
Use the formula “percentage change” =
This is a positive value so is a “percentage increase”
A percentage increase of 24%