# How to play Sudoku?

### Sudoku textbooks that are full of puzzles must meet three requirements:

Sudoku is a solitaire logic game in which the player is given a 9 × 9 cell grid, each of which can contain numbers from 1 to 9, or is blank or white, the grid should be deemed divided into 9 “UNDERGRATE” summoning 3 × 3 contiguous cell areas. given a grid in which only a few cells, 20 through 35, contain numbers. The goal is to fill in the blank spaces of a grid consisting of rows, columns and boxes with numbers 1 to 9, so that each row, column and region contains all the numbers 1 to 9 (one time each).

1. the initial numbers must form a symmetrical pattern relative to the center of the frame;

2. there must be a unique solution;

3.The initial number must be less than 35.

It’s worth pointing out that, contrary to what is often said, sudoku is a game of logic but not really math, let alone a sudoku game of numbers. The property of numbers is never used, nor is the fact that they never use numbers. To understand that, just think that the game would be exactly the same if instead of the first nine numbers they used the first nine letters of the alphabet or nine symbols that were different from each other (there was no need to even order between symbols).

## Rules

The game has one rule: you have to fill in grid proposals so that for each row, column and undergrate, each digit from 1 to 9 appears once and only once.

## Tool

To solve Sudoku is just logical reasoning, deduction, concentration and patience, and of course pencil and rubber, for every (and sometimes unavoidable) mistake.

## Solution

Like any well-constructed logical game, every Sudoku must recognize a single solution to allow the player to respond favorably to the results.

It should be noted that while a “simple” Sudoku (with 35 numbers already filled in) has only one solution, a “hard” Sudoku, (with 20 numbers) may have several solutions: on the other hand, Sudoku is empty, with only a definite space having the number of solutions. Very large.

## Difficulty

One of the Sudoku rules states that every Giglia is present, no more than 30 numbers.

The difficulty of a pattern increases as the number initially provided drops story about Sudoku, but it doesn’t depend solely on this: even its placement affects the difficulty level of the game.

Historically, this game is a much easier show to solve the ancient and famous game of logic and mathematics for which he is also Euler, it is a “Greek-Latin box.”