
Use the diagram to investigate the classical Pythagorean means.

Explore the lattice and vector structure of this crystal.

Farey sequences are lists of fractions in ascending order of magnitude. Can you prove that in every Farey sequence there is a special relationship between Farey neighbours?
Rajeev and Christian both explained their thinking about this probability problem very clearly.
In this article, we look at solids constructed using symmetries of their faces.
An article introducing continued fractions with some simple puzzles for the reader.
A java applet that takes you through the steps needed to solve a Diophantine equation of the form Px+Qy=1 using Euclid's algorithm.