Schoolhouse Rock! is a series of short, animated videos that use music to teach about grammar, science, economics, history, mathematics, and civics. The aim is to help kids learn things like historical facts and multiplications tables by learning songs.
Bob Dorough wrote and sang this song about the number "three," as a fun way for kids to learn their multiplication tables. It became the pilot episode for Multiplication Rock, the first season of the Schoolhouse Rock TV series.