How to Enter a Subscript in Excel. Properly formatting expressions such as "H2O" in your Excel spreadsheet requires the use of subscripts. Subscript formatting makes a letter or number appear ...

Hold "Shift-Option-Command-+" to enter subscript numbers in Adobe InDesign, PageMaker or QuarkXPress if you're using a Mac. Press the same command sequence to return to normal editing mode.

Learn how to add superscript and subscript buttons to the toolbars in Word, PowerPoint, and Excel in both Office 2004 and 2008.