If =sum() returns 0, then the cells with those numbers aren't really numbers.

You could try converting from text to numbers by:
select an empty cell
edit|copy
select the offending range
edit|paste special|check Add

If the =sum() doesn't change, maybe you got the data from a web site and your
values have those HTML non-breaking spaces in them.

David McRitchie has a macro that can help clean this:
http://www.mvps.org/dmcritchie/excel/join.htm#trimall
(look for "Sub Trimall()")

And if you're new to macros, you may want to read David's intro:
http://www.mvps.org/dmcritchie/excel/getstarted.htm

karen wrote:

I'm downloading data from a database into Excel; some of the cells have $0
values, but some are just blank. If I sum a row or a column which includes a
blank cell, I get an error message: #VALUE! How can I convert the blank
cells to zeros?
--
karen

--

Dave Peterson