The Department of Mathematics, National University of Singapore organized the first ever Sudoku competition in Singapore during our Mathematics Enrichment Camp of Tuesday, December 13, 2005. We had almost 250 contestants and the winner was Tan Zek Gian from Raffles Girls? School.

Tan Zek Gian from Raffles Girls?s School receiving the first prize from Professor Zhu Chengbo

Contestants at our Sudoku competition

There will be a lecture at the Mathematics Camp, but we hope to also conduct more lectures in the future. You can download a copy of the lecture notes.

The Mathematics of Sudoku

Sudoku is a logic puzzle where you are given a 9?9 grid made up of nine 3?3 blocks. The goal is to place the numbers 1 through 9 into the cells in such a way that each row, column and box contains each number exactly once. Some of the cells are given, and this is done in such a way that there is a unique way to fill in the remaining cells. The puzzles can be of varying levels of difficulty. They can be easy enough to appeal to anybody, while a mathematician will immediately be fascinated by the more fiendish puzzles and start thinking about algorithms.

Sudoku was invented in the US in 1979, but it only became popular when it was introduced in Japan in 1984. It took the UK by storm in late 2004 and quickly became a staple in most British papers. Here in Singapore the Today newspaper has a simple Sudoku on weekdays and a harder puzzle in the weekend edition. Many bookstores have a large selection of books with Sudoku puzzles.

I will describe some of the techniques for solving this puzzle and we will solve some puzzles together.

Source: www.math.nus.edu.sg