The goal of Sudoku is to fill the house of 9 with numbers so that every column, every row, and every 3x3 small nine-house section contains numbers between 1 and 9. The 9x9 grid will have some squares filled with numbers. What you have to do is use logic to fill in the missing numbers and complete the grid. Sudoku is rich in topics, divided into simple, intermediate, difficult, and expert four level modes, auxiliary error check, repeat item highlighting, note-taking function, uncertain digital note recording prompt function, at a glance Sudoku, as a digital puzzle, does not require you to have calculation and special math skills, only need wisdom and focus. Increase concentration and intelligence!