This Helix Value Maths Set contains a selection of essential mathematical instruments great for use in the classroom. It comes with a clear plastic 15cm ruler and matching protractor for measuring and drawing lines and angles plus two set squares for creating fixed 30 45 60 and 90 degree angles. The blue plastic compass with pencil makes it easy to draw arcs and circles. Finally theres a handy eraser and pencil sharpener with an anti-tamper blade for extra safety.