I happened upon this tweet when I got to work this morning:

Freeing imprisoned clones: finally a use for geometric series that isn't about computing interest http://t.co/FpJWxO73xI @numberphile #math

— Matt Caicco (@MatthewJCaicco) December 20, 2013

So I watched the fantastic numberphile video Pebbling a Chessboard. I wanted to get the kids to play the game and I didn’t have any checkers in the classroom, so I decided to program the game in Processing. Thankfully the programming went smoothly, and I finished it in time to have the Pre-Calculus class try to beat the game (it’s the day before winter break, and we just finished sequences and series). Fantastic timing.

Rules:

• Goal: remove all checkers from the green prison.
• If you click on a checker, and there is space to the right and above, then that checker will disappear, and two clones will appear to the right and above.
• Theoretically this game board extends to infinity to the right and above.

The game is hosted by openprocessing.org or hosted by recursiveprocess.com. It should work in any web browser, including smartphones. If you’d like to increase the checkerboard size, just go to the openprocessing.org site and “tweak” the code. The size of the board is set on the first two lines.

Enjoy!