Remove Duplication in Excel formulas with LET

Sample file: https://www.excel-university.com/remove-duplication-in-formulas-with-let Have you ever written a formula that repeats the same expression multiple times? I know I have. One simple example is IF((A1-B1)=0,0,A1-B1). Notice how the expression A1-B1 is used twice? This is a simple example of duplicating an expression within a formula. In general, we want to try to remove/minimize such duplication to make the formula cleaner and easier to manage. Historically, defined names have been able to help with this. Now, we have a new option ... LET.