Modular arithmetic

Learn about the rules for a group and the different groups of 4 elements by doing some simple puzzles.

Peter Zimmerman, a Year 13 student at Mill Hill County High School in Barnet, London wrote this account of modulus arithmetic.

Tom writes about expressing numbers as the sums of three squares.

Peter Zimmerman from Mill Hill County High School in Barnet, London gives a neat proof that: 5^(2n+1) + 11^(2n+1) + 17^(2n+1) is divisible by 33 for every non negative integer n.

A Latin square of order n is an array of n symbols in which each symbol occurs exactly once in each row and exactly once in each column.

An example of a simple Public Key code, called the Knapsack Code is described in this article, alongside some information on its origins. A knowledge of modular arithmetic is useful.

An introduction to the notation and uses of modular arithmetic