1. Mean, Median, Mode & Range

2. Mean A number that represents the centre, or average, of a set of numbers; to find the mean, add the numbers in the set, then divide by the number of numbers. For example, for the number set: 12, 15, 10, 11 The sum of these numbers is 48 (12+15+10+11=48) There are 4 number in the set. 48 divided by 4 = 12 The mean is 12.

3. Median The Median is the middle number when the data are arranged in numerical order. For example: 5, 7, 13, 27, 37 The Median is 13 for it is the middle number. For an even number of data, the median is the mean of the two middle numbers. For example: 5, 7, 13, 27, 37, 40 The 2 middle numbers are 13 & 27. Simply add 13+27 and divide by 2. The median for this set of data is 20.

4. Mode Mode is the number that occurs most often in a set of numbers; for example, in the number set: 8, 6, 10, 4, 7, 6, 9, 6 The mode is 6. In this example: 2, 10, 3, 2, 3, 45, 99 The mode is 2 & 3 In this example: 1, 3, 44, 13, 47 There is no mode

5. Range Range tells how spread out the numbers in a set of data are. It is found by subtracting the least value (smallest number) from the greatest value (largest number). For example: 2, 5, 11, 15, 20 20-2=18 The range is 18