Range and Spread
The range is the difference between the largest and smallest values and gives a simple measure of how spread out data is.
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The range is the difference between the largest and smallest values and gives a simple measure of how spread out data is.
- Range equals highest minus lowest
- Outliers can inflate the range
- Smaller spread means more consistent data
🧠 Quick quiz
Three questions. Score 2 or more to complete the topic.
What is Range and Spread?
Within Mathematics, which covers numbers, algebra, geometry, trigonometry and statistics from first principles to exam level, this topic explains Range and Spread. Maths builds step by step, so each topic here gives you a rule, a picture and a quick check you can use on homework and in exams.
Check that you can explain Range and Spread in your own words and give one example from everyday life. If you can do that, you have understood the core idea.
Understanding Range and Spread gives you a reliable method you will reuse in later maths units, in science lessons and in data work.
Range and Spread in detail
The range is the largest value minus the smallest and measures how widely data are spread. A small range means the values are close together and a large range means they vary a lot. Comparing both an average and the range gives a fuller description of two data sets.
The range is sensitive to outliers, so the interquartile range is often used instead. Spread tells you about consistency: two players may have the same mean score, but the one with the smaller range is more reliable. Always give averages together with a measure of spread.
How the interactive helps you understand Range and Spread
Watch the bar chart in the interactive. Use any sliders or buttons it offers to change the values and see how the bar chart responds.
Before you change anything, predict the result. Then change one value at a time and check whether your prediction was right. This is a quick way to build a correct mental model of Range and Spread.
Real-life uses and examples
- Use Range and Spread when comparing prices, discounts or recipe quantities in everyday life.
- Explain Range and Spread to a friend with a simple picture, such as a row of tiles or a bag of sweets.
- Spot Range and Spread in exam questions, where it often sits inside a short word problem.
Common mistakes to avoid
- Forgetting units, signs or brackets when you apply Range and Spread.
- Memorising the steps for Range and Spread without checking why they work.
- Learning the definition without testing it. Use the quiz and the interactive to check that you can apply the idea.
Frequently asked questions about Range and Spread
What is Range and Spread?
The range is the difference between the largest and smallest values and gives a simple measure of how spread out data is.
What are the most important points about Range and Spread?
The main points are: Range equals highest minus lowest; Outliers can inflate the range; Smaller spread means more consistent data.
Why is Range and Spread useful?
Understanding Range and Spread gives you a reliable method you will reuse in later maths units, in science lessons and in data work.
How can I practise Range and Spread?
Open the interactive at the top of this page and change the controls one at a time. Predict the result before each change, then take the three-question quiz. A score of two or more marks the topic as complete on this device.
Which topics are related to Range and Spread?
Related topics in Mathematics include Pie Charts, Cumulative Frequency, Counting Principles.