Sorry, I should have mentioned this, but I don't believe that I can use SQL to calculate the sum because I am using grouping in the table on the report.  I am performing the calculations as described but need to place the sum in a group footer row.  I am not sure that makes things easier or more difficult?  Is there not a way to place the sum of a detail row of a table into the group footer of a table?  This seems like it should be a basic function of the reportviewer tool.