The mean average is found by adding up all the numbers, and dividing by the number of numbers.
Mean average = total of quantities ÷ number of quantities
The median is simply the number that lies at the centre of a set of numbers, when they have been arranged numerically.
If a set of numbers has an even total, the median is the mean of the two middle numbers.
The mode is the most popular number in a set: in other words the one that occurs the most.
The range of a set of numbers is how widespread they are. It is found by subtracting the smallest from the biggest number.
Range = biggest number - smallest number