You must mean showing summary data in a header or footer? Never done it but I suppose if I was going to try, my footer controls would use Sum, DSum, a bunch of +'s or kludgy IIF expressions. However, I wouldn't go to all that trouble when I could probably base the report on a Totals query and have one detail row in the report. If I'm off base, you might have to explain your situation a bit more.
The more we hear silence, the more we begin to think about our value in this universe.
Paraphrase of Professor Brian Cox.