That's not add-up, that's counting. That's something else: if the two cells contain 1 and 3 for example, the SUM (add) is 4, but the NUMBER (count) is 2. And you can't add non-numbers.
That being said, the function to use is counta. See http://office.microsoft.com/en-us/excel-help/statistical-functions-HP005203066.aspx for all 'statistical' functions.
Kees
I'm trying to set up a formula in excel for the following;
-I'll be entering in random alphanumeric codes in cells
-I need to add these codes up simply if there is ANY data in the cell
-For instance if I have 3 cells with any data in them, I need to sum this up as 3. Possible?

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