check "Refer to the same cell or range on multiple sheets" in help
to make it so that you do not have to change the formulas, add a sheet at
the beginning called start and a sheet at the end called finish (or what ever
you want to call them"
=sum('start:finish'!A1) will sum all the sheets between, including any
shhets you add later between the two start and finish sheets

"Sean" wrote:

I am looking for a function that can add up cells across multiple
sheets

I could of course do =Sheet1!A1+Sheet2!A1 etc etc. Problem is that I
have 52 sheets each named after a week end date

My values are all in relative positions and I am looking to add these
up in a sheet called "Summary Report". I add a new sheet each week, so
in effect I'm looking for a formula that will add up all A1 values in
each sheet of the workbook expect anything in "Summary Report". Is
this possible?

Thanks