That's definitely not going to be useful. By doing this 15 numbers at a time you completely avoid needing to do any division anyway. print FB, i+1. i+2, Fizz, i

That's definitely not going to be useful. By doing this 15 numbers at a time you completely avoid needing to do any division anyway. print FB, i+1. i+2, Fizz, i+3, Buzz. i+4, ... i+14. Then increment by 15. Also, even with a very slow CPU you'd already run faster than can be perceived on a digital clock