How To: Calculate year over year sales via Excel array formula

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 613th installment in their series of digital spreadsheet magic tricks, you'll learn how to
add sales for the year from dates entered as text using the SUMPRODUCT and RIGHT functions and ampersand (&) join symbol. Learn abut TRUE-FALSE arrays and how numbers and text are different. See two different methods to convert numbers to text (lead apostrophe) and text to numbers (&"").