True, Harlan, but as a generality I think it wiser to suggest that users
keep the sheet with the summation formula(e) outside the "sandwich" to avoid
any chance of circular referencing.
Hopefully it avoids the re-posts with " it doesn't work...."

Regards

Roger Govier


Harlan Grove wrote:
Roger Govier wrote...
....

=SUM(First:Last!A1)
Of course, the sheet with the formula must be outside of the "sandwich"
created by First and Last.

....

No it doesn't. The only restriction on this particular formula is that
it can't be in cell A1 in any of the worksheets between First and Last,
inclusive, without causing circular recalc. It'd work just fine entered
into any other cell.