1. Percentage Change
Percentage change can also be called percentage increase, percentage decrease, percentage profit, percentage gain, percentage reduction or percentage loss.
When we calculate percentage change, we are determining how much something has changed relative to its initial value.
We use the percentage change formula:
1.1 How to calculate Percentage Change?
In order to calculate percentage change, we use the following methods:
- Work out change i.e. how much the value has changed using subtraction.
- Apply the percentage change formula:
3. Simplify the fraction if necessary using equivalent fractions.
4. Convert the fraction to a decimal.
5. Calculate percentage change.
Example: In 2000 the minimum wage for adults was £3.60 per hour. In 2016 it was £6.31 per hour. Work out the percentage increase in the minimum wage..
Solution:
Example: The table shows information about the population of a city.
| Population in 2001 | Population in 2011 |
| 4,20,000 | 4,80,000 |
John claims,
"From 2011 to 2021 the population of the city will increase by the same percentage as from 2001 to 2011"
He works out,
The population increase from 2001 to 2011 = 4,80,000 - 4,20,000 = 60,000
The population in 2021 = 4,80,000 + 60,000 = 5,40,000
Does the population of 5,40,000 match his claim?
Solution:
Example: Last year Aaniya paid £245 for her car insurance. This year she has to pay £883 for her car insurance. Work out the percentage increase in the cost of her car insurance.
Solution:
