The note
How schools teach it now
Year 6 teaches the mean as 'sharing out equally': add up the values and divide by how many there are. Median (the middle value in order), mode (the most common) and range (largest minus smallest) are usually Year 7 but appear in many 11+ papers.
5-minute kitchen-table activity
Roll a dice seven times and write down the scores. Your child puts them in order, then finds the mode, median, range and mean. Try it again with the family's shoe sizes.
Worked example
The mean of four numbers is 9. Three of them are 6, 8 and 11. What is the fourth number?
- The total of all four is 4 × 9 = 36.
- The three we know add up to 6 + 8 + 11 = 25.
- 36 − 25 = 11.
Answer: 11
Common mistakes to watch for
- Finding the median without putting the numbers in order first.
- Giving the range as '3 to 11' instead of one number (8).
- Dividing by the wrong count when finding the mean.
Encouragement
- Try saying
- “The mean is sharing out fairly. Let's try it.”
- Rather than
- “There are too many words to remember.”