Big Idea
Percent means out of 100, so percentages compare everything to a hundred equal parts.
Percentages
Convert percentages and solve percentage-of-amount problems.
Understand it first
Percent meaning
25% means 25 out of 100.
Useful links
50% is half, 25% is a quarter, and 10% is one tenth.
Of means multiply
Finding a percentage of an amount means finding that fraction of the amount.
Method Ladder
Use this same ladder every time you meet this topic.
- Convert the percentage into a useful fraction or decimal.
- Find simple percentages first, such as 10%, 50%, or 1%.
- Combine them if needed.
- Check that the answer is sensible.
Worked example: Find 20% of 45
- 10% of 45 is 4.5.
- 20% is double 10%.
- 4.5 x 2 = 9.
- Answer: 9.
Fix It Lab
Read these before the quiz. They are the traps that lose marks.
- Common mistakeTreating 20% as 20 instead of 0.20.
- Common mistakeForgetting that 100% is the whole amount.
- Common mistakeNot checking whether a percentage increase should make the answer bigger.
Top-mark challenge
Open challenge
A jacket costs £60 and is reduced by 15%. How much is taken off?
Write full working and one sentence explaining the method.
10-question unlock quiz
The quiz is now on separate pages. You answer one question, then the next question opens. Finish Question 10 to complete this mission.
Start Question 1