In Kelly Thompson's toy-filled preschool classroom, blocks are king. And castle. And race car ramp. And demolition set. And they are everywhere. As the 4-year-old students create towers and garages, ...

There are, New York City public school principal Kristina Beecher discovered, an awful lot of types of play blocks. There are wooden blocks, cardboard blocks, magnetic blocks, clear plastic blocks, ...

Our "Tools of the Trade" series is taking a look at some of the iconic objects that form a vital part of our educational lives. For an upcoming piece, I'm reporting on how young children learn through ...