Euclid's Algorithm

Euclid's Algorithm is one of the oldest algorithms known to  mankind. It was found in Euclid's Elements, something dates back to 300 B.C.

When Euclid came up with the algorithm, mathematics was not known as it is today; in fact, he used geometrical methods in his discovery, as algebra was not known at that time, as a branch of mathematics.

Euclid's algorithm is used to find the HCF - Highest Common Factor - or GCD - Greatest Common Divider - of two numbers.

The following animation shows how it determines the HCF of two numbers:


euclid's algorithm


The corresponding flow chart for the Euclid algorithm is as follows:


euclid's algorithm flowchart


Please work out the following questions to complement what you have just learnt.