Multi-base arithmetic blocks (MAB) are the most frequently used physical materials for teaching about decimal numbers, despite published reservations about their appropriateness. This paper presents ...

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 ...

Most people know just one way to multiply two large numbers by hand. Typically, they learned it in elementary school. They’re often surprised to find that there are a variety of ways to do ...