**Range**

The *range* of a set of numbers is the highest number minus the lowest number.
So, in the set { 2,5,8,2,1,4,3] the highest number is 8 and the lowest number is 1,
so the range is

8 - 1 = 7 (range)

If there are any negative numbers in the set,
then you have to be really careful, because subtracting a negative number is
the same thing as adding the positive number. So, in the set

5 -1 6 -2 0

The highest number is 6 and the lowest number is - 2, so the range is:

6 - (-2) = 6 + 2 = 8

Think of it as the distance between 6 and - 2 on the number line, like this:

---|---|---|---|---|---|---|---|---|---|---|---|-- ...
-3 -2 -1 0 1 2 3 4 5 6 7 8 ...
|<------------ 8 -------------->|

So, here is a problem for you:

What is the range of this set of numbers?

9 4 8 9 2 -1 3 4