Year 8: Percentage change

This cheat-sheet helps you calculate percentage changes in numbers. A percentage change tells you how much a number has increased or decreased compared to its original value.

Formula

The formula to calculate percentage change is:

Percentage Change = (New Value - Old Value) / Old Value * 100

Types of Change

Percentage Increase

If the result is positive, it’s a percentage increase. This means the new value is higher than the old value.

Percentage Decrease

If the result is negative, it’s a percentage decrease. This means the new value is lower than the old value.

Example

Example: Original Value = $50, New Value = $60

Percentage Change = (60 - 50) / 50 * 100

= (10 / 50) * 100

= 0.2 * 100

= 20% Increase

Another Example: Original Value = $80, New Value = $60

Percentage Change = (60 - 80) / 80 * 100

= (-20 / 80) * 100

= -0.25 * 100

= 25% Decrease

Remember to always state whether it’s an increase or a decrease.