Try one of these:

This will sum the odd numbered rows:

=SUMPRODUCT(--(MOD(ROW(D7:D17)-ROW(D7),2)=0),D7:D17)

This will sum the even numbered rows:

=SUMPRODUCT(--(MOD(ROW(D7:D17)-ROW(D7),2)=1),D7:D17)

--
Biff
Microsoft Excel MVP


"physiker" wrote in message
...
I would like to know how to sum every other entry in a column of numbers.
This is useful to perform numerical intergration. Thanks.