I will definitely look at the Life of Fred books - thank you!

And yes, the SCAT DD took was supposed to be for grades 4-6 (or something like that) and measures reasoning to a degree. According to CTY, DD is qualified to take the highest level math courses offered (for her age range or however they work that...I obviously need to do more research). So it seems that DD must have some math potential...???

I do appreciate the responses. I believe I've seen ALEKS mentioned here and I will search that now. It may be another option.