Walk Along Number Line 11-20 as Children begin to move on from the basics of learning 1-10, help them gain confidence with higher numbers with this 11-20 counting line. An active way to learn addition and subtraction with a hop, skip and a jump. The mat has a carpet exterior and a non-slip rubber base for indoor or outdoor use. Team up with the separately sold 1-10 line for more versatility. Detailed teacher's notes included. Size: 240mm x 2.4m.