5. Using Functions in Formulas
A function is a predefined formula for making a specific kind of calculation. Functions make it quicker and easier to write formulas.
For example, say you need to add up a column of numbers like the one in Figure 1. It’s perfectly acceptable to write a formula using cell references separated by the addition operator (+) like this:
Figure 1. Using the SUM function makes it easier to add up a column of numbers.
But rather than enter a lengthy formula, you can use the SUM function to add up the same numbers like this:
The SUM function is only one of over 300 functions ...