How to solve Sudoku puzzles techniques

Goal

The goal of Sudoku is to fill a 9x9 grid with digits so each column, each row and each of the nine 3x3 sub-grids that compose the grid, contains all of the digits from 1 to 9. The same digit may not appear twice in the same row or column or 3x3 region.

The solution of a Sudoku puzzle is only one, so there is only one right way to solve it without repeating a number in a row, column or region.

Notes

From the goal of the game we can deduce two basic premises:

If a number doesn’t appear on a row, column or region, one of the remaining cells of that area must contain that number.

If a number appears on a row, column or region, none of the remaining cells will contain that number.

Techniques list

1. Basic techniques

2. Intermediate techniques

3. Advanced techniques

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