Something different today: If you are a math neophyte, you will love the add-in created by Brad Hunter, called Math Easy. Brad writes:

The product is straight forward; a "Math" button is visibly added to the Excel toolbar, performing "Addition", "Subtraction", "Average", etc. No prior Excel experience is required. Hopefully beginners can use Math Easy as a stepping-stone to learning more advanced math. Visit http://www.excelmatheasy.com to download the software, view screenshots, and gain additional information.

The price is about $5 - a great investment. Check it out.