sum = 0 in error

[pdmartin58]

I have a column of numbers that sums erroneously to 0. If I add each cell A1+A2+A3, etc it returns the correct value but the sum function always returns 0. I've ensured that all the field formats are numerical. Any ideas what's causing this problem?

 

[Eric W]

It's still possible to have a number stored as text in a cell formatted as General, or some number format. Try this and see what happens:

=SUMPRODUCT(A1:A3+0)

 

[pdmartin58]

Still returns a 0.

 

[Joe4]

I've ensured that all the field formats are numerical.

That won't matter if the entries were entered as Text. Changing the field format after it has been entered will have no effect on it.
What does this formula return?
=ISNUMBER(A1)

If it returns FALSE, you have text entries, not numerical ones.
You can use Text to Columns on column A to convert those all to numbers.