Formula that will address the changes in each cell reflected on bottom of worksheet

Hello all, i am trying to figure out how to write a formula in a ws. i will try to explain what i am attempting to do, I have my base formula as follows. =sum(b2-c2-d2+e2) then since this is a monthly sheet i start the formula in b3 as =(f2) so that the amounts tally up for the next day. I drag the corner down to the next cell to carry over the formula, my question is this.....since the work sheet is long how do i write a formula that will address the changes in each cell that will reflect on bottom of worksheet? I am attempting to keep a running tally in column b34 to reflect the numbers changing above. sorry for the long question, i know this is likely a simple formula....but i am stumped.
Michael

Hello, here is the attachment (i hope). thanks
Michael

Thanks for the reply Jeff, it looks like it is trying to add the numbers from column "b", i need it to reflect what is in say "b12",B13 and so on with a running tally. Notice that each day is less. Sorry for any confusion in my post, but with the page being a little long i was just trying to be able to see at the bottom the total fuel left on board without scrolling back to the top. again thanks for your help.
Michael