I start by explaining that I'm not very good at math, and it's because of an experience I had in elementary school. Teacher asked what 6-3 was, and I said "6". I demonstrate using 6 cards. She sends me to the office. I show the principal, and she calls my mom. I show her, and she says, "wait 'till your father gets home!". He gets home, I show him, and he says, "that looks like a pretty good trick". I agree and offer to demonstrate to the audience. "What's 6-3?" Answers vary. I say, "it's 3!... You'd better pay attention in math!"

This is a great list - one of them teaches prop card production?