Percentage change
AQA GCSE Biology calculation · part of the free Calculation Climb
How much something has gone up or down, as a percentage of where it started: (change ÷ starting value) × 100. You meet this in osmosis (mass change of potato chips).
How to do it — step by step
- change = final − starting value.
- percentage change = (change ÷ starting value) × 100.
Worked example
A potato chip goes from 5.0 g to 5.5 g.
change = +0.5 g → (0.5 ÷ 5.0) × 100 = 10% increase
Now practise it — free
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