We can define the range as the difference between the highest value and the lowest value.
Consider the dataset 12, 11, 9, 8, 15.
Range = Highest value - Lowest value = 15 - 8
= 7
Consider the dataset 9, 9, 2, 10.
Range = 10 - 2
= 8
Similarly, for the dataset 5, 6, 2, 10, 13
Range = 13 - 2
= 11