"Theo" wrote...
. . . I know that my cell has a
blank. . . .

So you've checked it using =ISBLANK(C2) which returned TRUE? Or do you mean only
that =LEN(TRIM(C2)) returns 0?

. . . My original question was to see if excel can
interpret a blank as a 0. It will do so for a sum
function but not for a cell add. A blank is not the same
a null value. A null value will be interpreted as a 0
for both a sum and a cell add. You are correct that I
can test for a blank cell.

Now you're using your own peculiar terminology rather than standard Excel
terminology. First, 'null' is ambiguous - if you don't mean the error value
#NULL!, what do you mean *PRECISELY*? A cell containing no formula? As for
'blank', why would anyone believe it meant anything other than a cell for which
ISBLANK returns TRUE? If you want 'null' to mean a cell for which ISBLANK(cell)
returns TRUE and 'blank' to mean a cell for which TRIM(cell) returns "", then
you need to state that explicitly at the outset of your post so that others
could have some hope of understanding what the heck you mean.

If you're misusing the term 'blank' to mean a cell for which TRIM(cell) returns
"", then =1+(cell&"0")+2 returns 3 if Transition Formula Evaluation is disabled,
and =1+VALUE(cell&"0")+2 returns 3 all the time. TRIM isn't needed in eitehr.

--
To top-post is human, to bottom-post and snip is sublime.