Summing a Variable Number of Cells

[Guest]

I have a spreadsheet that calculates values for each year out to a given
date. If I want to know what the sum of some specific time period is and not
necessarily the entire column, how would I instruct excel to only add a
variable amount of rows on a specific column?

For example, if I chose 5 years and I have numbers going out 30 years, what
formula could I add to my sum field to sum only the first 5. Or if I wanted 6
years, would it also sum the first 6 entries and so on.

 

[Don Guillett]

where e1 contains 5 or 6 or?
=SUM(F1:OFFSET(F1,E1-1,0))