Electronic sudoku

Sudoku (Su Doku) is a logic based placement puzzle, sometimes referred to as Number Place in the United States and Canada.

The New York Times Touch SuDoku contains more than 800 puzzles, all selected by world-renowned puzzle expert Will Shortz.

The aim of the puzzle is to enter a numeral from 1 through 9 in each cell of a 9×9 grid made up of 3×3 sub-grids - called "regions", starting with various numerals given in some cells - the "givens". Each row, column and region must contain only one instance of each numeral. Solving the puzzle requires patience and logic. Its grid layout will remind you of other newspaper puzzles like crosswords and chess problems.

Sudoku puzzles:

Sudoku puzzles do not require any knowledge of mathematics to solve. Move mouse pointer over the sample puzzle to see the solution. However, Sudoku does require logic and reasoning. The use of numbers offers one method of identification – letters, colors, symbols or anything else can offer identifiers for the cells. Some children's games use animals.