For a start, you don't need the SUM function if you are not asking it to sum
two or more arguments. You can use either SUM(A1,B2) or just =A1+B2.

To deal with blank inputs, you could use =IF(COUNT(A1,B2)=2,A1+B2,"") if you
want both inputs to be non-blank, or =IF(COUNT(A1,B2)=0,"",A1+B2) if you
want either to be non-blank.
--
David Biddulph

"Stig - tame racing driver" wrote in
message ...
Is there a way of adding blank cells and without getting a result of 0

E.g.

=sum(A1+B2) Answer is 0 is there a way of just have a blank cell

Cells A1 and B2 are blank
----------------------------------------

All this to make conditional formatting to work:-
Blank cell = no colour
0 = Green
1 = Yellow
Between 2 and 999 = Red


Hope you can help
Regards