Find the IQR
- Find lower quartile Q1.
- Find upper quartile Q3.
- Subtract Q1 from Q3.
Answer: Q3 20 and Q1 12 gives IQR 8
📊 Statistics
Quartiles
Learn quartiles with a GCSE-style explanation, help guide, worked example, practice question and flashcards.
Global XP
Level 10 / 100 XP
1. Explanation
Key idea
- Quartiles is part of statistics and appears often in KS3–GCSE maths.
- The interquartile range measures the spread of the middle 50%.
- Use the worked model, help guide, interactive question and flashcards to practise quartiles until the steps feel automatic.
Real-life examples
- Shopping, sport, travel, science, design and everyday decisions all use this skill.
2. Visual
Quartiles learning map
Understand the key idea → follow the help guide → practise a question → check your method → build speed with flashcards.
3. Help guide
How to tackle Quartiles
- Learn the rule: The interquartile range measures the spread of the middle 50%.
- Worked model: Find lower quartile Q1. Find upper quartile Q3. Subtract Q1 from Q3.
- Try the interactive question without looking at the answer first.
- Use the flashcards to test the rule, the method and a common check.
4. Worked examples
Step-by-step working
5. Interactive questions
Try it yourself
If Q1 = 6 and Q3 = 14, find the IQR.
6. Flashcards
Master quick recall
Flip each card, then choose whether you know it or need more practice.
0 mastered
FrontRule for Quartiles
BackThe interquartile range measures the spread of the middle 50%.
FrontExample answer: If Q1 = 6 and Q3 = 14, find the IQR.
Back14 - 6 = 8.
FrontCommon check for Quartiles
BackCheck units/notation, compare with an estimate, and make sure the answer matches the question.
7. Finish
Complete this topic
When you have read the examples, tried the question and reviewed flashcards, claim your topic completion XP.