Well, that isn't really true. You CAN summarize calculations, you just can't INSERT summaries on them.
You didn't say what the desired summary was or at what level, but if you want a grand total of these calculations, use a variable. Create two formulas:
//{@accum} to be placed in the group section containing the calculation:
whileprintingrecords;
numbervar sumx := sumx + {@yourcalculation};
//{@display} to be placed in the report footer (group footer if summary is for a higher order group):
whileprintingrecords;
numbervar sumx;
If you want the result displayed in some higher order group, you need a reset formula in that group header:
whileprintingrecords;
numbervar sumx;
if not inrepeatedgroupheader then
sumx := 0;
-LB