text: For example, if you have 100 in cell A1 and 37 in cell A3 and you want your answer in cell B10, type the following formula in cell B10:\n=A1-A3\n\nMake sure your formula does NOT have an apostrophe (') before the equal sign.  In other words, you don't want this:\n'=A1-A3\n\nThe apostrophe tells it you want text and the equal sign tells it you want a formula.