alt Hacker Newsmaybe outing myself as a dinosaur, but "back in my day" the calculator came with a book that detailed exactly how to use it. Both the high level basic language and the low level system language. Not knowing how to use it is simply a failure to Read The Fucking Manual.
You can read the manual all you want, but if you don't know basic algebra, trig, calculus, etc, you are not going to have any idea how to apply or use much of anything that the manual describes with regards to actually doing math with a graphing calculator. There is a base level of knowledge required.