For over a century, views of young childrens's mathematics have differed widely. The recent turn of the century has seen a dramatic increase in attention to the mathematics education of young children. Our goal is to synthesize relevant research on the learning of math from birth into the primary grades from multiple perspectives.

Most everyone agrees that effective mathematics teaching involves "meeting the students where they are" and helping them build on what they know. But this is easier said than done. In this important new book for pre- and in-service teachers show how "learning trajectories" help diagnose what mathematics a child knows.