Skip to content
Auralith Learning

Year 8 · Maths · Percentages · Lesson 3

Percentage change

Calculate percentage increase and decrease, including profit and loss, and use multipliers to find a percentage change.

Whiteboard video lesson: Percentage change

27-minute video lesson

Teaching, worked examples and 20 practice questions solved step by step.

Watch free for a month

What your child will learn

  • Find the change between two amounts
  • Calculate a percentage increase
  • Calculate a percentage decrease
  • Find percentage profit and loss
  • Use a multiplier to find a percentage change

The method

  1. Find the change (the difference).
  2. Divide the change by the ORIGINAL amount.
  3. Multiply by 100.
  4. Say whether it's an increase or a decrease.

Key words: percentage change, original, increase, decrease, profit, loss.

Worked examples

The first three practice questions from the lesson, with every step.

Question 1

A price changes from £20 to £25. Find the percentage increase.

  1. Step 1: Change: £25 − £20 = £5
  2. Step 2: change/original = 5/20
  3. Step 3: 5/20 × 100 = 25%

Answer: 25% increase

Question 2

A price changes from £50 to £60. Find the percentage increase.

  1. Step 1: Change: £60 − £50 = £10
  2. Step 2: change/original = 10/50
  3. Step 3: 10/50 × 100 = 20%

Answer: 20% increase

Question 3

A price changes from £80 to £100. Find the percentage increase.

  1. Step 1: Change: £100 − £80 = £20
  2. Step 2: change/original = 20/80
  3. Step 3: 20/80 × 100 = 25%

Answer: 25% increase