Union division: Find some identical numbers in two lines of three parallel nine squares, and then use nine squares to find the positions of the numbers in the other line. This method is very suitable for advanced Sudoku. But it will be more difficult to master in the early stage.
Patrol method: find out some numbers that appear frequently in each nine-square grid, and then get their positions in other nine-square grids. This method is generally applied after union division.
Hypothesis: This method is to randomly fill in a number at a certain position and then deduce it. Although it may eventually lead to contradictions and negative conclusions, it is still practical in advanced Sudoku.
Exclusion method: this method is a bit difficult to operate, that is, observe each line or nine squares. If there is no other number to fill in a position, then fill in the remaining numbers and try to see if you can draw a conclusion.
Undetermined method: this method is very suitable, that is, temporarily determine a number in a certain area, and then use it to exclude it. Generally speaking, this method can be used with other methods.
Rank method: this method is generally used in the final stage, using the breakthrough from the ranks to complete the nine squares.
Characteristics of Jiugongge:
Jiugongge game rules, there are nine numbers from 1 to 9, and there are three squares horizontally and vertically. Think about how to make the sum of three numbers on two diagonal lines of each row and column equal to 15. This game not only tests people's numerical reasoning ability, but also tests people's thinking logic ability.
Jiugongge game plays a great role in people's thinking exercise, and people have realized the educational significance of Jiugongge since ancient times. It has a great influence for thousands of years, and it has appeared in literature and film and television. Jiugongge was originally called "Luo Shu" and now it is also called "Rubik's Cube".