# SUM i to n without Using Cell References

#### Scooterman23

##### New Member
In excel, SUM(number 1, [number 2], ...) is used to sum an array of cells, however, I'm trying to go back to the mathematical usage of summation:

n
Σ f = f(1) + f(2) + ... + f(n-1) + f
i = 1

I'm trying to use this to plug in values to a function such as PV(i%, n,, F) to sum present worth values with a constant i% and F value and a varying n without making an array of PV values.

I have a feeling that excel won't be able to do this but I'd like to try.

### Excel Facts

Which came first: VisiCalc or Lotus 1-2-3?
Dan Bricklin and Bob Frankston debuted VisiCalc in 1979 as a Visible Calculator. Lotus 1-2-3 debuted in the early 1980's, from Mitch Kapor.

#### pgc01

##### MrExcel MVP
Hi

Not clear to me

You mean you want add the PV values using a sequence of n's, something like

=PV(3%, 1,, 100)+PV(3%, 2,, 100)+PV(3%, 3,, 100)+ ... + PV(3%, 10,, 100)

?

If not, please post a clear numerical example with the expected resutl.

#### Scooterman23

##### New Member
Hi

Not clear to me

You mean you want add the PV values using a sequence of n's, something like

=PV(3%, 1,, 100)+PV(3%, 2,, 100)+PV(3%, 3,, 100)+ ... + PV(3%, 10,, 100)

?

If not, please post a clear numerical example with the expected resutl.

That is almost exactly what I'm trying to do. I may try to do something like =PV(3%, 3,, 100)+PV(3%, 6,, 100)+PV(3%, 9,, 100)+ ... + PV(3%, 12,, 100), but that would be simply 3 times whatever solution is.

Thanks!

#### pgc01

##### MrExcel MVP
You can use

=SUM(PV(3%, {3,6,9,12},, 100))

or, since you have an arithmetic progression with common difference of 3 also

=SUM(PV(3%, 3*{1,2,3,4},, 100))

which makes it easier to adapt if you have many terms. For ex. for 10 terms:

=SUMPRODUCT(PV(3%, 3*ROW(INDIRECT("1:10")),, 100))