The mode is the value that appears most often — the number that repeats, not how many times it repeats, and not the largest number. The range measures how spread out the data is: subtract the smallest value from the largest. Range is a distance, so it is one number that describes the gap, never the biggest value on its own and never the two ends added together. Tally the values to find the mode; find the highest and lowest to find the range.
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
- mode
- the value that occurs most often
- range
- the gap from the smallest value to the largest
- frequency
- how many times a value occurs
Worked examples
Mode of 2, 5, 5, 5, 8
- 1.Tally: 5 appears three times.
- 2.The value that repeats is 5.
= 5
Range of 4, 7, 9, 3
- 1.Largest is 9, smallest is 3.
- 2.9 − 3 = 6.
= 6
Range of 12, 4, 8, 15
- 1.Largest is 15, smallest is 4.
- 2.15 − 4 = 11.
= 11
For parents
Method: Tally marks for the mode; highest-take-lowest for the range.
What to say: For the mode ask 'which number turns up most?'; for the range ask 'how far from lowest to highest?'.
Common mistakes:
- Giving the frequency of the mode instead of the value.
- Picking the largest value as the mode.
- Forgetting to subtract the smallest (or adding the ends) for the range.