You may also like

problem icon

Where Do We Get Our Feet Wet?

Professor Korner has generously supported school mathematics for more than 30 years and has been a good friend to NRICH since it started.

problem icon

Exhibition of Knots

A review of the website

problem icon

Links and Knots

Some puzzles requiring no knowledge of knot theory, just a careful inspection of the patterns. A glimpse of the classification of knots, prime knots, crossing numbers and knot arithmetic.

Torus Patterns

Stage: 5 Challenge Level: Challenge Level:3 Challenge Level:3 Challenge Level:3

An insight to this problem will most likely be gained by physically trying to colour in various regions of the squares on paper, where you can get a feel for how everything fits together.

Start by working out which parts of the squares are connected together. If you colour one region of the square, you will see that the colours of certain other regions of the square immediately follow by considering connected parts of the square.