It's always great when your friends find useful nuggets for you.  Alfred Thompson blogs about his experience with the Math Add-in for Microsoft Word: 

The Microsoft Math Add-in adds computational and graphing capabilities to the Equation Tools Ribbon of Word 2007.
With the Microsoft Math Add-in for Word 2007, you can:

  • Plot a function, equation, or inequality in 2-D or 3-D
  • Solve an equation or inequality
  • Calculate a numerical result
  • Simplify an algebraic expression

I tried this out and it is very easy to use with lots of helpful explanations and "how to" instructions. You have to have Word 2007 of course but the add-in itself is a free download. More information and the download are here.