EDEXCEL GCSE FOUNDATION MATHS - What is Percentage Change

Edexcel GCSE Foundation Maths: Percentage Change

Percentage change is a way of expressing how much a quantity has increased or decreased. It's a very useful skill to have in real-world situations, like understanding price changes, economic growth, or even your own progress in learning.

Understanding the Formula:

The formula for calculating percentage change is:

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

Breaking it Down:

1. New Value: This is the value after the change has occurred.
2. Original Value: This is the value before the change.
3. Subtract the Original Value from the New Value: This tells us the amount of change.
4. Divide by the Original Value: This gives us the proportion of change relative to the original value.
5. Multiply by 100: This converts the proportion into a percentage.

Example:

Imagine the price of a loaf of bread increases from £1.00 to £1.20. To calculate the percentage increase:

1. New Value: £1.20
2. Original Value: £1.00
3. Change: £1.20 - £1.00 = £0.20
4. Proportion: £0.20 / £1.00 = 0.2
5. Percentage: 0.2 * 100 = 20%

Therefore, the price of the bread has increased by 20%.

Key Points:

• Positive Percentage Change: Indicates an increase in the quantity.
• Negative Percentage Change: Indicates a decrease in the quantity.

Practice:

Try these examples to test your understanding:

1. A shop reduces the price of a shirt from £20 to £15. Calculate the percentage decrease.
2. A company's profit increases from £100,000 to £120,000. Calculate the percentage increase.

Remember: Percentage change is a powerful tool for understanding how things change over time. By mastering this skill, you'll be better equipped to analyze data and make informed decisions.