First thing I'd do is to make sure that calculation was set to automatic:
tools|option|Calculation tab

If that's not the solution, then I'd check to make sure that the cells referred
to in the formula are really numbers.

So for =sum(a1,b1)

Select A1
format as General (or number--just not text)
then hit F2 and then enter (to reenter that value)

Same thing with B1.

Does that formula evaluate correctly?

=======
If you have lots of these cells to fix, you may want to try David McRitchie's
routine to clean the data:

http://www.mvps.org/dmcritchie/excel/join.htm#trimall
(look for "Sub Trimall()"

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

Greg wrote:

I am having an issue with a spreadsheet.

Seems that some, not all the cells that have formulas are working.
When I created the spreadsheet I configured some cells to show the total of
some other cells it worked without any problems. Now when I open the
spreadsheet some of the configured cells will not work. By this I mean they
will not add up numbers from the other cells. This problem is intermittent.

Im using simple formulas such as =SUM(A1,B1)

How can I fix this?

Thanks in advance
Greg

--

Dave Peterson