I don't remember exactly, but I think we were only allowed the simplest calculators in middle school (none before), and scientific calculators in high schools (

I don't remember exactly, but I think we were only allowed the simplest calculators in middle school (none before), and scientific calculators in high schools (mostly for the trigonometric and power functions). I got to use a TI in university, but never used it that much as I've got the basic function graphs memorized.