Order the numbers from least to greatest. Then subtract the Greater number by the Smaller number.
Example:
4, 6, 2, 3, 4, 10, 4, 7
Step One- Order from least to greatest: 2, 3, 4, 4, 4, 7, 10
Step Two- Subtract the Greatest by the Least: 10-2
Answer would be 6.
(This is just an example. Don't use on answer unless it asks for an example)