I'm going to differ with Peco on this occasion, for one picky reason: Suppose your sum is 234.501, and you use ROUND(234.501,2)? The answer is then displayed as "234.5", whereas you (I suppose) want "234.50". My solution is to use TEXT(234.501,"0.00"), which turns 234.501 into "234.50".

Now, if this works for you then we can stop there, but it has one drawback: The whole cell cannot be used for further calculation, because it's a character string "Total: 234.50" rather than the value 234.5. There is a way you can have both the "Total:" and the numeric value available for calculation.

Go back to the formatting dialogue for this cell, and select the Custom category. Fill in the following as the custom format string:Excel fills in the format just as though you'd typed in a standard number format but preceded by the word "Total: ", and still lets you use that cell for arithmetic calculation. If you don't need to do arithmetic on that cell then you may as well use whichever method is easiest; but this method can be pretty handy on occasion.