Automatically append given text to the result from a formula

Question

I have the following formula:

=$AF$46

How would I append text to its result?

e.g., if =$AF$46 is showing up as 0.00, how would I make it show 0.00% done?

^{Editor's note: The question was later extended to "restrict" formatting of the formula's result to 2 decimal places. Some answers predate this requirement; others cover either of the two possible interpretations of "restrict": "up to 2 decimal places" and "exactly 2 decimal places".}

Answer 1

You can add text via a formula like the following (if you place this in a different cell than AF46):

=AF46 & "% done"