In your formula, Dave, the SUM() functions are doing nothing, and more
significantly the OP doesn't just want to add the row 3 and row 9 values, he
wants the rows between included.
--
David Biddulph

"Dave F" wrote in message
...
=SUM(T3-(T3*I3))+SUM(T9-(T9*I9))

"Rick G. Garibay" wrote:

I am trying to do a sum across rows in which the operand is determined by
taking the value in the cell and subtracting it from said value times a
percentage.

For example:
(T3-(T3*I3)) + (T4-(T4*I4)) + (T5-(T5*I5)) + ...

I'd like to avoid the manual function shown above and instead go with
something like:

SUM((T3-(T3*I3)):(T9-(T9*I9)))

The SUM function does not appear to support this. Is there a way to
accomplish this without resorting to a manual function?

Thanks,

Rick