First find the row, column and palace that are only one number apart, and fill them all in, then find the one that is two, and judge according to other rows, columns and palaces. Practice often, and you can solve Sudoku in 40 seconds if you are skilled.

To do Sudoku, we should start with the best conditions, expand our positions and finally make a comprehensive breakthrough. Sudoku is a logical math game that uses paper and pen to calculate. Players need to infer all the numbers of the remaining space according to the known numbers on the 9×9 disk, and satisfy each line.