A Sudoku puzzle comprises a 9x9 grid, divided into 9 smaller 3x3 subgrids (or boxes), totaling 81 cells.
At the beginning, some cells contain numbers 1 to 9, while others are blank.
To solve the puzzle, fill in the blank cells with numbers 1 to 9, following this simple rule: each number in a given row, column or box must be different. This ensures no repetition of the same number within any row, column, or box.
Examine the solved Sudoku puzzle above. Notice that in each row, column, or box all the numbers from 1 to 9 are present, and none are repeated. One particular row, column and box are highlighted for your reference.
A valid Sudoku puzzle is solvable, meaning that it has one, and only one, possible solution. Every puzzle in our books has precisely one solution.