I know that it's possible in Excel to toggle between displaying values and displaying formulas. I'm required to turn in assignments for a statistics class as a printed Excel sheet showing both the formula and the result. Right now the instructor makes us either copy the formula and paste it as text next to the computed value, or copy the value and paste it next to the formula. This is very inefficient, prone to error (if you change the formula or values after doing the copy-paste), and generally a waste of time.

Is there any way to have Excel show the formula and its value in the same cell? If not, is there any function which will display the formula from a referenced cell as plain text, e.g. =showformula(A1) which would print out =sum(A2:A5) instead of 25 (if those were the formula and value of cell A1)?

I'm using Excel 2010, but a general answer that works for any recent edition of Excel would be nice.