Doing math for fun, enjoyment, entertainment and/or to pleasure ones self.
Dude1: Hey! whats that nerd over there doing with that calculator?
Dude2: Probably mathterbating
Dude1: Dude! sick he could at least go to the bathroom to do dat
Dude2: Gotta do what you gotta do
Fogey/fogy /fougi/ sl. (early 18C+, orig. Scot) old-fashioned, stuck-in-the mud.
Person with old fashioned ideas which he is unwilling to change: Come to the disco and stop being such an old fogey!
You think me an old fogeyand an old tory, his thoughtful voice said. I saw three generations since O’Connel’s time. I remember the famine. Do you know that the orange lodges agitated for repeal of the union twenty years before O’Connel did or before the prelates of your communion denounced him as a demagogue? You fenians forget some things. (James Joyce, Ulysses. Penguin Books,1992. p. 38)