Sudoku

a Japanese puzzle game

Sudoku is a logic-based, number-placement puzzle. In classic Sudoku, the objective is to fill a 9 × 9 grid with digits so that each column, each row, and each of the nine 3 × 3 subgrids that compose the grid (also called "boxes", "blocks", or "regions") contain all of the digits from 1 to 9. The puzzle setter provides a partially completed grid, which for a well-posed puzzle has a single solution.

Sudoku has different difficulty levels. It can be played in the following levels;
Easy, Medium, Hard, Expert

For more information go to wikipedia Sudoku

Go Play

Demo page by Clarissa van der Zwan