Reverse Percentages: Finding Original Values

This page explains the concept of reverse percentages, focusing on how to calculate original values after percentage changes. It provides two practical examples to illustrate the process.

The first example demonstrates how to find original amount before percentage increase. It shows the calculation for determining Connor's original wage before a 6% increase, resulting in £212.

Example: Connor receives a 6% increase on his weekly wage, now earning £212. To find his original wage:

1. Calculate the total percentage: 100% + 6% = 106%
2. Set up the equation: 106% = £212
3. Calculate 1%: £212 ÷ 106 = £2
4. Find 100%: £2 × 100 = £200

The second example illustrates how to calculate original price from sale price. It shows how to determine the original price of trainers that are on sale for £79.20 with a 20% discount.

Example: Trainers are in a 20% off sale for £79.20. To find the original price:

1. Calculate the sale percentage: 100% - 20% = 80%
2. Set up the equation: 80% = £79.20
3. Calculate 1%: £79.20 ÷ 80 = £0.99
4. Find 100%: £0.99 × 100 = £99

Highlight: These examples demonstrate the importance of understanding percentage relationships and how to work backwards from a given value to find the original amount.

Vocabulary: Reverse percentage - the process of calculating the original value before a percentage change was applied.