Math Teachers at Play 20

The new Math Teachers at Play Carnival is up at Denise's Let's Play Math! blog. Besides the interesting puzzle she starts with, and the hilarious math FAIL images, there were a few posts I found especially interesting:

• Ashley Allain's post on computing fractions using Scratch, a new, kid-friendly programming language.
• Rachel Lynnette documents her use of a free symmetry game that looks promising.
• I'll be using this cone problem on a test, I think. Pretty elegant. Wonder if my students read this?

Due to the new monthly structure, there was a heap of submissions this time around. Check it out!