Explanation
A mean in maths is the average of a data set, found by adding all numbers together and then dividing the sum of the numbers by the number of numbers.
For example, with the data set: 8, 9, 5, 6, 7, the mean is 7, as 8 + 9 + 5 + 6 + 7 = 35, 35/5 = 7.