Absolute Beginners Guide to Microsoft Office Excel 2003

One of your grade school math teachers probably introduced you to the order of operations , which governs the order in which a series of mathematical equations is performed. Excel follows this standard order of operations, as well. In every formula, Excel performs the equations from left to right in the following order, which gives some operators precedence over others:

Keeping precedence in mind is important when you are entering formulas because the order of operations determines the result. For example, if you wanted to determine the average of the values in cells A1, B1, and C1, and you entered =A1+B1+C1/3, Excel would probably generate the wrong answer. Rather than total the three values and then divide by three, as you might expect, Excel first divides the value in C1 by three and then adds that result to A1+B1. It calculates this way because division takes precedence over addition. So, how do you correctly determine this average? You must enclose in parentheses the operations you want performed first. In this example, you need to total A1 to C1 first. To do that, enclose the cell addresses in parentheses: =(A1+B1+C1)/3. This tells Excel to total the values first and then divide the total by three.