Summing cells with null values

[Michael]

I create cells with null values, so as not to fill the
spreadsheet with zeros, with formualas like

=if(a3>0,a3*100,"")

However when I sum these values for a total row, I'll get
#value! as a result. I would prefer to have either a blank
in this cell or even a zero, anything but #value! Is there
an easy way to do this? Some type of function for the
summed cells to convert them to zero or something? Thanks.
Michael

 

[Peo Sjoblom]

Michael,

if you use the sum function it disregards null strings as opposed using

=A1+A3+A5+A8 and let's say A3 has a "" string will return value

=SUM(A1,A3,A5,A8)

will not.