Sudoku is an American pastime that became popular in Japan in 1986 and became known internationally in 2005.
The objective is to fill in a grid of 9 × 9 cells, forming a total of 81 cells divided into sub-grids of 3 × 3 (called boxes or blocks) with the figures from 1 to 9. The game is presented with some numbers already arranged in some cells (called given numbers or clues), as shown in the figure to the left. and the figure on the right shows the game solved.
The rules of the game are simple and easy to learn for beginners and do not require mathematical knowledge, despite being a game based on numbers. There are sudokus of different levels of difficulty. Practice in performing sudoku puzzles allows you to progress in the complexity of the exercises. It is not necessary to complete the exercise all at once; You can start a sudoku puzzle at one time of the day and finish it at another, or even any other day.
The game consists in that no figure can be repeated in the same row, column or block. The solution is unique, that is, there is only one correct way to solve each sudoku puzzle. The objective is to fill the empty cells with a number in each one of them in such a way that each column, row and block contains the numbers from 1 to 9 only once.
Beginners are recommended to start with easy sudoku puzzles. Starting with the difficult ones can be very frustrating, when it should be an entertaining and fun hobby. By practicing with the easy ones, you can learn to solve the more difficult ones.
Use pencil and eraser. Sometimes, especially at the beginning, frequent mistakes are made, even to the point of erasing everything that has been done. Some people prefer to use a pencil for doubtful numbers and a pen for those they think are safe.
Each sudoku puzzle has only one solution. This implies that only one possible number from 1 to 9 can go in each box. Only the numbers that are the only possible numbers in each box should be considered as definitive. If in any case more than one can go, examine the rest of the boxes and save that for later.
Start with the numbers that appear the most times. It is usually easier to guess the missing numbers the more numbers there are of the same value. If it is the case of having the number 3 8 times, the only 3 that will remain to be placed will be at the intersection of row and column where it does not appear.
This type of game stimulates the brain. When it is not stimulated it tends to focus on negative thoughts and leave the person with a general feeling of unhappiness.
Just as exercising increases physical vitality, playing mental challenges like Sudoku can also help energize the mind. A more active and fit brain is the first step towards looking at life and the world from a more positive and healthy perspective.