Select the text that you want to format as superscript or subscript.
On the Format menu, click Font, and then click the Font tab.
Select the Superscript or Subscript check box.
what you can do is instead of putting the 2 up there, you can instead use the karot (the ^ symbol, shift+6) symbol, which also shows up on many graphing calculators, and followed by the two.
Do you mean how do you write it out? Select the exponent, then click Format fonts, then check the superscript box to raise the exponent. (is that what you mean?)