New to Microsoft Excel? Looking for a tip? How about a tip so mind-blowingly useful as to qualify as a magic trick? You're in luck. In this MS Excel tutorial from ExcelIsFun, the 583rd installment in their series of digital spreadsheet magic tricks, you'll learn how to use the AVERAGEIF & IFERROR functions with absolute and mixed cell references to create a large table of conditional average calculations (averaging with criteria).