First, find the row or column with the most numbers or the 3×3 small grid to do it. Secondly, there is a quick way to find the intersection. Find the same number in two rows of three parallel nine squares, and then use nine squares to get the position of another row of numbers. This method is suitable for advanced Sudoku.

Find out the number that appears frequently in every nine squares and get the position of the number in the other nine squares. This method is applied after the first method.

Extended data:

Find the same number in two rows of three parallel nine squares, and then use nine squares to get the position of another row of numbers. This method is suitable for advanced Sudoku.

Find out the number that appears frequently in every nine squares and get the position of the number in the other nine squares. This method is applied after the first method. This method is the key to solve the problem, which is easily overlooked by ordinary people. Observe each row or nine squares. If there is a place where no other figures can be filled in, fill in the remaining figures.

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