They were offered to me. The contest by the Head of the Computer Science from the university I attend and the latter by the new principal, when I was leaving the school. I work there ever since each summer.
My combination is Math and Computer Science. But it's pretty easy to have more jobs, when they don't interfere with each other. I work in the school only in August and September. And I work on the contest in June and July the most.
Oooh teacher? That seems like a really nice job! Are you teaching a specific subject? And I'd never be able to handle multiple part-time jobs at a time :P
I study to be teacher right now. But I few part-time jobs. I'm creating questions and graphics for local contest and help janitor in my old elementary school during the summer break.