Create your own Number Bug with these magnetic pieces. Body segments have numbers on one side and are blank on the reverse to enable the teacher to hide a number for the child to identify. Perfect for teaching numbers 1-20. Size of head: 5 cm (2") to top of antennae. Size of body segment: 3.3 cm (1-5/16") long. This brightly coloured set includes 20 body segments numbered 1-20 and 4 bug heads.