What is the median?
The median is not in the primary curriculum (it is taught in Key Stage 3), but some 11+ papers include it. Below: what it means, a worked example, the mistake to watch for and an 11+ question.
The answer
The median is the middle number when a set of numbers is put in order.
What it means
Put the numbers in order, smallest to largest, and pick the one in the middle.
If there is an even number of values, there are two in the middle. The median is halfway between them.
A worked example
Find the median of 3, 9, 4, 7 and 5
- Put them in order: 3, 4, 5, 7, 9.
- The middle one of the five is 5, so the median is 5.
The common mistake
Forgetting to put the numbers in order first. The middle of 3, 9, 4, 7, 5 as written is 4, but the median is 5.
How it comes up in the 11+
Find the median of 12, 7, 15, 9, 20 and 7.
Answer: 10.5
- In order: 7, 7, 9, 12, 15, 20.
- There are 6 numbers, so the middle two are 9 and 12.
- Halfway between them: (9 + 12) ÷ 2 = 10.5.
Try it yourself
It opens on 3, 9, 4, 7 and 5 from the worked example: see them put in order with the middle one picked out.
Type a list of numbers to see the mean, median, mode and range, each with its working.
Related words and practice
More maths words
Questions parents ask
What if there are two middle numbers?
Add them and halve the answer. For 2, 4, 6 and 10 the middle two are 4 and 6, so the median is 5.
Why use the median instead of the mean?
One very big or very small value can drag the mean a long way. The median stays in the middle.
Knowing the words is half of an 11+ maths question
11+ papers use maths vocabulary without explaining it. The free diagnostic checks maths, English and both kinds of reasoning, and shows what to practise next. No card is required.