I am finally making the switch from Windows to Mac and one big impediment/irritant is in the switch from Word for Windows to Word for Mac. I do a lot of mathematical work and have a large number of Word documents with equations in them from the Word 2010/2011 equation feature. In the Windows version, this is just a Pi symbol that I click to start typing an equation, and I can insert functions, summations, fractions, exponents, things like that really easily. I have Word 2008 on my Mac right now and none of those documents will even open. I could try updating to the newest version of Office, but I'm worried that I'll do that, they still won't work, and I'll be out a lot of money.
I'd like to not only open all these documents but also to continue writing mathematical documents the same way I'm used to on Windows. What can I do?