Thanks, the custom state did the trick, a bit of a hassle but a good work around.
I put this question in the OOO thread because if OOO was implemented with () available then I would enter: ListPrice * (1 - Discount). I have to do 1-Discount * List Price. The other alternatives in this thread were more complex than necessary given I can rearrange the order for this simple equation. This may help others getting started and coming across this issue and like me they might be searching for order of operations help.