Here's a nice shortcut for the superscript function:
Ctrl+Shift+"+" (i.e., Ctrl+Shift+"Plus key")
You can either select the number first, then use the key combo, or vice-versa.
Then use Ctrl+Spacebar to continue typing normal-size charaters.
Ctrl+Spacebar removes all formatting that is not built into the style.
Also, for subscripts, use: Ctrl+Shift+"-" (i.e., Ctrl+Shift+"dash")
Hope this helps.
Kamran.