GCSE MATHS • HIGHER TIER
Range Made Simple
Learn how to identify the highest and lowest values, calculate range and compare the spread of datasets.
Clear method
Exam practice
Worked proofs
Range in Four Moves
1
Identify
Find the highest value in the dataset .
2
Locate
Find the lowest value in the dataset .
3
Subtract
Calculate highest value − lowest value .
4
Interpret
Use the range to describe or compare how spread out the data is .
What You’ll Learn
Understand Range
Know that range is a measure of spread .
Use the Formula
Apply Range = Highest Value − Lowest Value .
Work with Different Data
Calculate ranges involving repeated values, decimals and negatives.
Compare Datasets
Use range to compare variation.
Understand Limitations
Recognise how outliers can affect the range.
The Range Formula
Range = Highest Value − Lowest Value
This formula is one of the easiest formulas in GCSE Statistics, but students must be careful to identify the correct highest and lowest values.
Worked Proof: Range
Step-by-Step Method
- 1. Identify the largest value.
- 2. Identify the smallest value.
- 3. Subtract the smallest value from the largest value.
- 4. Write the answer clearly.
More Worked Examples
1
Question: Find the range of 3, 7, 9, 12, 15
Highest value = 15
Range = 15 − 3 = 12
2
Question: Find the range of 20, 25, 18, 30, 12
Highest value = 30
Range = 30 − 12 = 18
3
Question: Find the range of 5, 5, 5, 5.
Highest value = 5
Range = 5 − 5 = 0
4
Question: Find the range of 8, 14, 22, 17, 10
Highest value = 22
Range = 14
- Common GCSE Mistakes
- Values: Identify the correct highest and lowest values first.
- Order: Subtract lowest from highest, not the other way around.
- Negative numbers: Take care when subtracting a negative value.
- Decimals: Check decimal subtraction carefully.
- Meaning: Do not confuse range with an average.
- Exam Tips
- Write down the highest and lowest values before calculating.
- Use Range = Highest Value − Lowest Value.
- A larger range means the data is more spread out.
- Check signs carefully when negative numbers are included.
- Remember that frequencies do not change the highest and lowest data values.
- Consider the effect of outliers when interpreting range.
Skills Used in Range
Measures of Spread
Highest and Lowest Values
Subtraction
Negative Numbers
Decimals
Comparing Datasets
Frequency Tables
Statistics and Data Handling
Ready to Practise?
Watch the Range Tutorial
Step-by-step walkthroughs of Range with clear methods and exam tips.
Frequently Asked Questions
The range is the difference between the highest and lowest values in a dataset .
Range = Highest Value − Lowest Value .
It means the data values are spread out over a wider interval .
It means the highest and lowest values are the same, so there is no variation .
No. Use the highest and lowest values, regardless of their frequencies .
An unusually high or low value can significantly increase the range .