Calculate and add running percentages in Excel. Click Evaluate multiple times. Download the Excel file and choose one of the IF formulas explained on this page.
To create a formula with references highlight the cells you want to use then select an empty cell and enter the formula.
Type the negative sign - for the subtraction operation. This video shows how to do simple math. Also learn how to work with exponents and basic mathematical functions. This Excel tool helps you understand a formula.