>I am creating two summed fields within a report (TOTHRS & TOTCHG) and need to divide TOTCHG by TOTHRS to get a percentage. So far I haven't had any luck in getting this to work. Any suggestions?

When you create each variable, what are you putting in the Value to Store textbox? A field name? And did you check the Option to SUM? When you do that, you will have sums to calculate the percentage with.