I've written such a software for my Maths classes in 5th to 9th grade. Instead of doing my homework, I've programmed all the new stuff we've learned (calculate

I've written such a software for my Maths classes in 5th to 9th grade. Instead of doing my homework, I've programmed all the new stuff we've learned (calculate gcd and lcm, primes, factorization, geometry, stuff like that...), entered my homework and let my software compute the results. I later even implemented a solver for linear and quadratic equations which I was pretty proud of. I did all this programming first in QBASIC, than in PowerBASIC which gave me a nice speedup. Fun thing is, since I was quite young back than, I didn't knew how to define functions in BASIC which complicated my code quite a bit. I showed this software (which I've called ADDIMATH) to my math teacher, and he loved it! He even bought one copy for 0.50 Deutsche Mark on a 1.44MB floppy. He proudly told parents and other teachers about my software and allowed me to use it for my homework as long as I wouldn't give the software to my classmates.