Question on excel (in Off-topic)

I'm looking for a quick and easy solution to an excel puzzle I'm trying to solve.
I'm reasonably proficient on excel, but I can't get my head around it at the moment...

I have a group of 20 cells.
I'm entering random numbers into random cells within the group of 20. I'd like to be able to work out the average of the sum total entered into the 20 cells.

What's the formula that I must enter into my "totals" cell ?

Obviously I could use =Sum(A2:D6)/x but that doesn't work well as x could be 1 or 20 depending on the data entered.
I want excel to work out 'x' by itself and calculate the real average total for me.

You can always put the average function on another sheet in the same workbook and use =average(Sheet1!A1:ZZ65000) or whatever the max is in Excel, I cant recall.

=SUM(A1:A20)/COUNT(A1:A20)

I guess thats what you're asking for. not terribly sure :P

Oh, of course, the =average works, which is why i was getting confused with what you're asking...

The spreadsheet is quite complicated with numerous worksheets and I want to use the correct formula for working out my averages in many of them.

Anyway, I'm not quite sure I understand what you mean Tez :)

D'oh, posted before I saw your reply Daz.

That does the job just perfectly - thanks !