32 or 64 bit of office 2010 on 64 bit windows 7

I bought a Microsoft office 2010 that 32 or 64 bits is stamped on the box.
I assume that the single DVD disk contains both 32- and 64-bits office programs. That sounds a little stange to me. Here is another question:
My computers run 64 bits windows 7. On Microsoft office webpage. it described that "Microsoft recommends 32-bit Office 2010 for both 32-bit and 64-bit operating systems. Office 64-bit is optimized for advanced data ". I am not an advanced user. So I am confused. Could someone advise which bs (32 or 64) of Office should I install?.

Why the confusion?

I'd follow what the web page says: "Microsoft recommends 32-bit Office 2010 for both 32-bit and 64-bit operating systems".

True, I have also installed 32bit version on W7 64bit, following recommendation from Microsoft as posted above.

Cheers,
Miki