Sudoku

Sudoku means "single number in an alloted place" in Japanese and doesn’t require general knowledge, linguistic ability or even mathematical skill. It's fun and mildly addicting.

The aim of the puzzle is to fill in the blank spaces in the grid so that every column , every row and every 3x3 box contains the numbers 1 through 9, without repeating any.

History:
In 1783, Leonhard Euler, a Swiss mathematician, devised 'Latin Squares', which he described as 'a new kind of magic squares'. Euler had come up with a grid in which every number or symbol appears once in each row or column. More than two centuries later, the difference for Sudoku players is that the grid is subdivided into blocks of nine.

A man from Matamata, New Zealand, was to become responsible for a global outbreak. Wayne Gould, a judge who had moved to Hong Kong, was shopping in Tokyo in March 1997. While he waited for one shop to open, he browsed in a bookstore. 'As soon as I saw the grid with the empty squares, I felt very tempted to fill them in. Over the next six years I developed a computer program that makes up Sudoku puzzles on the spot.'

For a daily Sudoku:
http://www.su-doku.net/daily_sudoku_printable.php