Use the SUM() function!
It ignores text.

=Sum(A1:A110,B5:B15)
=Sum(A1,A33,B4,C2,C25,Z15)

--
HTH,

RD

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Please keep all correspondence within the NewsGroup, so all may benefit !
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"John Krsulic" <John wrote in message
...
I am trying to create what I would call an if/then formula in Excel 2003.
If
someone types the letters PTO into a cell have tat equal zero in the
formula.
I have a sum formula of a set of cells I want Excel to be able to add a
zero
into the formula if someone types the letters PTO into the cell. My
formula
works great until someone types letters into a cell then - of course -I
get a
value error in the cell.