If the last four digits of my phone number are placed in front of the remaining three you get one more than twice my number! What is it?

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.

We continue the discussion given in Euclid's Algorithm I, and here we shall discover when an equation of the form ax+by=c has no solutions, and when it has infinitely many solutions.

Use Euclid's algorithm to get a rational approximation to the number of major thirds in an octave.

This article sets some puzzles and describes how Euclid's algorithm and continued fractions are related.