Range is the distance between the smallest and largest numbers in a data set (set of numerical values). When using a set of numbers, oftentimes you will be asked to find the range. All you need is a knowledge of basic math and you can find the range of a set of numbers.
Write down your set of numbers. As an example, we will use the set: 9, 8, 6, 10, 5, 4 and 13.
Order the numbers in ascending order (smallest to largest): 4, 5, 6, 8, 9, 10, 13.
Subtract the smallest number in the set from the largest number: 13 - 4.
Write down the result: 13 - 4 = 9. The range for this example is 9.