I would like to add 2 columns and display the results in a 3rd column and
keep a running balance. A "check" register is really what I would like to
set up.

Would I write the function in the "c" column for example?
=sum(A1+B1)

then for the next row that the info will go into cell C2
=sum(C1+A2+B2)

I was wondering how to write out the function so that I don't have to do it
for each cell. Something like a variable N?