You need to be familiar with percentage increase and decrease calculations, which find amounts after a percentage change. 'Reverse percentages' is the term often used to find the amount before a percentage change, when you only know the amount after. It is therefore like 'going backwards' on the percentage change.

A good way to perform percentage increase and decrease calculations is using the multiplier. This is explained in the first video. The second and third videos then explain how to apply this to reverse percentages.

Key points to answering questions

  • Decide whether you are finding the amount before or after a percentage change.
  • Decide whether the percentage change (applied to the amount before) is an increase or decrease, and hence find the multiplier.
  • Setup your calculation, as either forward or reverse, using the multiplier.

Example videos

Video: https://drive.google.com/a/challoners.org/file/d/0ByH41whuUvC_V1BNUnVWczV6NHM/preview

Video: https://drive.google.com/a/challoners.org/file/d/0ByH41whuUvC_UzVlbWg2Y0l1Vzg/preview

Video: https://drive.google.com/a/challoners.org/file/d/0ByH41whuUvC_SnRhZjlZei1UclU/preview

Practice questions

Reverse percentages - questionsReverse percentages - solutions