Sudoku

The first US Sudoku championship was help in Philly last weekend. It was hosted by the famous puzzlemaker, Will Shontz. About 800 people competed in the competition according to the Philadelphia Inquirer's website. (They are the sponsor.) Participants competed in three categories and then later in 12 age groups. This was the largest live puzzle tournament ever held in the U.S.

Sudoku is a logic game where you fill 81 squares with numbers from 1 to 9. Number can not be repeated in a vertical or horizontal row, nor may they be repeated in the nine square blocks. Although invented by American Howard Garns in 1979, these puzzles were called Numbers Place. The Japanese popularized the puzzles under the name Sudoku, meaning "only single digits allowed", or something close to this depending on what site you consult.

Free games abound on the Internet. Try: http://www.websudoku.com/, www.krazydad.com/sudoku, http://www.sudoku-puzzles.net/!