We recently wrote about how infinitely large sets are not all the same size as each other, but we were a bit vague about what we meant by a set. The people who invented set theory also started out ...

Math Park is available to stream on pbs.org and the free PBS App, available on iPhone, Apple TV, Android TV, Android smartphones, Amazon Fire TV, Amazon Fire Tablet, Roku, Samsung Smart TV, and Vizio.

When I was a child, a new way of teaching math was introduced and soon became popular. Often called the “new math”, this approach to math included an attempt to build up all of math from the concepts ...