Back when we were doing quadratic equations; I wrote a program on my TI-84 that would ask which parts of the equation you already had, and would fill in the rest for you.
My teacher liked it so much he bought a transfer cable for those calculators so he could get a copy for himself. Then used to to grade tests.
Oh I would have been so pissed. I was programming on my calculator 24/7 instead of my classes.
I wrote a sudoku "editor"
I put that in quotes because I had a grid that could be navigated, arrows moved, storing the numbers, had number entry down. And when it was time to implement the solver, I learned the hard way what p vs np is.
Oh god I remember doing that too. Those "programs" were the best. I even mad sure to make the code long, so that even if someone thought to take a look at the code they would have to scroll for a while to find the notes.
What always annoyed me was having to draw charts by hand. Just let me put the data in a computer for god's sake, the rest of the working is there... I did actually write a python function for one of my assignments which was fine, but they told me not to do it for the exam.