Sudoku has its origins in a XVIII century’s Suiss game named ‘Latin Squares’. The first jigsaws were published in the end of the XVIII century in France. However, the game we now know as Sudoku was invented in 1979 by Howard Garns, with the name 'number place'. As we know it today, Sudoku appeared in Japan in 1984 as a diminutive of the expression ‘Sūjiwadokushinnikagiru’, meaning that the numbers are limited to one occurrence only. Sudoku is one of the most popular games of the last few years, existing nowadays many versions of the game. In a 9x9 Sudoku grid the goal is to fill in the line, columns and 3x3 grids with number 1 through 9 without repeating them. This is a good game to practice focus and mental skills. In this game you have to plan well, execute correctly, and evaluate the work done, in a cycle which will lead to the correct completion of the grid.