One of the most useful calculations to be able to perform is determining the mean or average of a set of numbers. You'll use this calculation throughout science classes, but actually everyone taking a class should learn how to do it because it's how you can calculate and check your own GPA. I've written up a quick example of how to calculate the mean or average
that you can use. Also, many calculators can calculate the mean for you... you just have to enter in the numbers you are averaging.