Solve one-step word problems using a visual model & a problem-solving process. Warm up with a Mystery Math Mistake to hunt for the mistake in adding two 2-digit numbers using a decomposition strategy.

A set of guidelines adopted by 45 states this year may turn children into "little mathematicians" who don't know how to do actual math. A few weeks ago, I wrote an article for TheAtlantic.com ...

Every few months, the Internet eats itself over some kind of viral riddle or illusion, each more infuriating than the last. And so, like clockwork, this maddening math problem has gone viral, ...