Sum by row in report (Analytic)

Hi Experts,

I have the requeriment that reflect in the follow example of report:

Column 1 | Column2

2             | 4

5             | 7

8             | 9

I was created the follow key figure:

"Column1"*"Column2"

The SAP C4C made the follow equation:

(2+5+8)*(4+7+9) = 15 * 20 = 300

But I need that the system made the following equation:

(2*4)+(5*7)+(8*9) = 8+35+72 = 115

Can any body help ?