1. Percentage Change OCR Module 8

2. Change? An Increase A Decrease

3. For example Increase £24 000 by 3% 3% of 24000 = 24000 x 3 100 = £720 Total = £24 720 103% of 24000 = 24000 x 103 100 = £24 720 MULTIPLIER of 1.03

4. For example Decrease £17.60 by 15% 85% of 17.60 = £14.96 Left with 85% of 17.60 = 17.60 x 0.85 MULTIPLIER of 0.85

5. What is the Multiplier for … An INCREASE of 12% 25% 33% 17.5% 1.12 1.25 1.33 1.175 A DECREASE of 12% 25% 33% 17.5% 0.88 0.75 0.67 0.825

6. The Original Value? Often, we are given a price AFTER an increase or decrease To calculate this, we complete a REVERSE PERCENTAGE calculation

7. For example After a 10% salary increase, David earned £38500 What was his salary BEFORE this increase? NEW SALARY is the OLD SALARY plus 10% MULTIPLIER = 1.10 110% of OLD = 38 500 OLD x 1.10 = 38 500 OLD = 38500 ÷ 1.10 OLD SALARY = £35 000

8. For example A shirt was ON SALE for £26.00. It had been reduced by 20%. What was the original price? SALE PRICE is the OLD PRICE less 20% MULTIPLIER = 0.80 80% of OLD = 26.00 OLD x 0.80 = 26.00 OLD = 26.00 ÷ 0.80 OLD PRICE = £32.50