In HS, i recommend HP 39G for Math and Physics. U can plug in many equations into the calculator. Then u can go into a screen where u enter all da values for all da variables except for one. It will then solve for the unknown variable. It is allowed on provincial exams so don't worry. Only problem is a lot of the statistics function is missing on da HP39G and u gotta do some of the stuff manually on da calculator. (like getting the Standard Normal Bell Curve thingy) HoweverI survived and got 95 on math 12 so no big deal. It is cheaper than the Ti-wuteva too. Strongly recommended~!!!
Oh ya, i did have 2 expension cards for it. Meta Kernal 3.0 and a 256kb ram card.
You can find math software package on par with Maple for HP48GX on www.hpcalc.org