The median is the middle value once the numbers are in order. Always sort first — the middle of the unsorted list is not the median. With an odd count there is one middle number. With an even count there are two middle numbers, and the median is halfway between them: add them and divide by two. The median ignores how extreme the end values are, so one very large number does not drag it, which is what makes it useful.
Explore this idea with maths tools
Maths you can move
Build 8 + 5
Tap two gold counters to fill the ten-frame.
8 in the frame + 5 waiting. The total stays the same.
Words to know
- median
- the middle value when the data is in order
- sort
- put the numbers in order from smallest to largest
- outlier
- a value far from the rest that the median resists
Worked examples
Median of 7, 2, 9, 4, 5
- 1.Sort: 2, 4, 5, 7, 9.
- 2.The middle number is 5.
= 5
Median of 8, 2, 6, 4
- 1.Sort: 2, 4, 6, 8.
- 2.Two middles 4 and 6: (4 + 6) ÷ 2 = 5.
= 5
Median of 1, 2, 3, 4, 100
- 1.Sort: 1, 2, 3, 4, 100.
- 2.The middle is 3 — the 100 does not drag it.
= 3
For parents
Method: Line the numbers up on cards, then point to the middle.
What to say: Make sorting a separate, deliberate step before anyone looks for the middle.
Common mistakes:
- Taking the middle of the unsorted list.
- For an even list, adding the two middles but forgetting to halve.
- Using halfway between smallest and largest instead of the middle value.