Or, rather, Math Teachers at Play #9 is up at Homeschool Bytes (who have hosted MTaP before as well!) The theme is Game Time, and the post has several games and magic tricks.

Speaking of games, did you know that they have a bunch of math games at coolmath? You can play Mancala (although it seems like there are a million variations to that), the Tower of Hanoi, and lots of other stuff. Watch out for the sound effects, because that can get a little overwhelming at times. (Fifteen minutes later: I just finished a game of Sudoku, helped out by the 8-9 year olds in the living room. Why didn’t I play with this site before? I think Sudoku is one of the best ways to teach Proof by Contradiction, since once you get past the infinitude of the natural numbers, the infinitude of the primes, and the square root of ___ is irrational it’s harder to come up with good examples.

(Incidentally, in courses where I teach that the square root of 2 is irrational I usually make it homework to show that the square root of 3 is irrational. Once they’re comfortable with that, I have them prove that the square root of 4 is irrational, and to find the flaw in the proof. This proves to be really challenging to the sophomore math majors.)

I think I’ll end my stream of consciousness here.