UK: Try an image search for 'Helix Oxford Maths Set'
Compasses, dividers, protractor, setsquares (that we don't use these days) and a 15cm ruler. Pencils, sharpener, rubber. Usually a stencil for lettering and a leaflet with geometry definitions.
Available from supermarkets, stationers and cash and carrys right now because it is GCSE Maths exam time.