I mean, I honestly don't mind grad-school-rec-writing season, but wtf kind of question is "how many students have you taught or advised [in your career]?"
I've been doing this for seventeen years. Hell if I know. One (1) crapton? Possibly metric crapton?
(I haven't taught large-lecture courses, but I have taught a few mid-sizers -- 75-150 -- in my time. So the answer, given that I have a fair few "repeat offenders," is probably somewhere in the low-to-mid thousands.)