Averages
What is the median?
The median is the middle value when you put the numbers in order.
How to find the median
1. Write the numbers in order from smallest to greatest. 2. Cross off one number from each end at a time. 3. Keep going until you reach the middle. 4. The value left in the middle is the median.
Good to know
This works neatly when there is an odd number of values, because there is exactly one value in the middle.
Worked examples
Numbers not in order: heights
- Five plants have heights: 133, 137, 134, 131, 132 cm.
- Put them in order: 131, 132, 133, 134, 137.
- Cross off 131 and 137, then 132 and 134.
- 133 cm is left in the middle.
Answer: The median is 133 cm.
Numbers already in order: 1, 2, 3, 4, 5
- The numbers are already in order.
- There are 5 numbers, so the middle one is the 3rd.
Answer: The median is 3.
Where you see this in real life
- The middle height when children line up from shortest to tallest.
- The middle price in a list ordered from cheapest to most expensive.
- The middle score in a set of test results.
Key words
- Median
- A type of average which is the middle value after the data has been arranged in order.
- Average
- A way to describe a set of data. It could be the most usual value or the middle value.
- In order
- Arranged from smallest to greatest.