The game is played with numbers but it has nothing to do with mathematics. It does not require any knowledge of addition or multiplication. The came is composed of nine squares from left to right and top to down, which, in turn, are divided into nine squares again. The player inserts numbers from 1 to 9 into these squares. Sudoku is a Japanese-style crossword solved with numbers instead of words. Clues are offered in accordance with the difficulty level of the puzzle. Every square is divided in itself and there can be only one of each number in each column, row and small square. Sudoku experts say that the game is simply played by reasoning, which is the reason why the Sudoku craze that broke out in Europe last year has now spread out to the United States and the number of players rises every day. Sudoku is an intellectual numerical puzzle that enhances the IQ. It is a game that you can play on the bus, on the train or during your lunch break.