How do I do a columnar cumulative sum?

[Don Calder]

Being a Excel newbie, I'm looking for some help. How do I write
formula where cell A1 + B1 = C1 but also where C2 is a cumulative su
(i.e. a running total) when cell A2 + B2 is included, down say 2
rows?

Thanks for any help anyone can give me

 

[duane]

in cell c1

=sum(a$1:b1)

copy this down column

 

[Frank Kabel]

Hi
in C2 enter
=C1+A2+B2
and copy this down