"Three Is a Magic Number" is a song written by Bob Dorough and popularized by the animated television series Schoolhouse Rock!. The song teaches children about the significance of the number three through catchy lyrics and a memorable melody. It emphasizes how many things in life come in threes, such as the three primary colors and the three stages of life. The song also highlights the concept of multiplication, showing how three can be a building block for understanding larger numbers. Its playful approach makes learning about numbers fun and engaging for young audiences, reinforcing the idea that math can be enjoyable.