I try to stay firmly away from marijuana when it comes to school.
I find when I've learned, studied, and taken tests all sober, the outcome is greatest.
If I had to choose, though, it would be high on tests, not during class. I need to be completely sober while learing so I'll comphrehend fully and store it well. I'm much better at recalling the information when I'm high if I learned it sober rather then learned it stoned.
I mean, I have taken a math anal. test stoned and still got a B. But I would never be able to pass a single math test if I had tried to learn the stuff high-- I really just couldn't.