Sudoku guide
Sudoku rules
Sudoku has simple rules, but the puzzle becomes interesting because every placement affects the whole board.
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5
3
6
1
5
9
8
6
8
3
7
6
6
2
8
4
9
5
7
9
The goal
Fill the 9x9 grid so every row, every column, and every 3x3 box contains each number from 1 to 9 exactly once.
The core rule
A number cannot repeat in the same row, column, or box. If a number already appears in one of those areas, it cannot be placed there again.
How to start
Look for rows, columns, or boxes that already contain many numbers. The fewer missing numbers there are, the easier the next placement is.
Practice