Group Theory is thought of as 'advanced mathematics', something studied at university, but in fact it is found in many day-to-day things, including solving puzzles and playing with triangles https://magisoft.co.uk/alan/misc/game/maths/ The Puzzle Square is an online puzzle that is a bit like a two-dimensional version of Rubik's Cube. This series of presentations introduces various aspects of mathematics that are useful for learning about the square and other puzzles.