Formulas can often be difficult in Excel. If you aren’t a math whiz, you may not recall the standard order of precedence that Excel uses. For example, within a formula, multiplication is performed before any addition or subtraction and calculations within parenthesis are performed before any others. If you do not understand how Excel is performing a calculation, you can use the Evaluate Formula option to make it clearer.

Within Excel, click on the cell you want to evaluate.
From the Tools menu, point to Formula Auditing and click Evaluate Formula.
Click the Evaluate button to watch as Excel evaluates each step of the formula.