Read up on what the MOD function does.

Essentially, it is taking columns C through W (which is column numbers 3
through 23), and dividing by 2. If the remainder is 1 (i.e.: an odd column),
then it will be SUMmed, if the remainder is 0 (i.e.: even columns between C &
W, such as D, F, H, etc), then it will be ignored.
--
John C


"PaulinaDi" wrote:

This formula worked fine but I didn´t understand what ,2)=1 makes to the
range selected. What do these 2 numbers mean?

"John C" wrote:

=SUMPRODUCT(--(MOD(COLUMN(C9:W9),2)=1),C9:W9)

Hope this helps.

--
John C


"PaulinaDi" wrote:

I have a table where I need to Sumarize different columns.

Eg:
=C9+E9+G9+I9+K9+M9+O9+Q9+S9+U9+W9 but in this row E9 and M9 have no data as
all these cells have their own formula from other files like
='[2008-dosbocas-porcompr.xls]DosBocas (mat)'!G6, ecc. So, in this case these
E9 and M9 have no values.

The problem is that I am not able to use the first formula as I get a #value
error.
What am I doing wrong?