Use “ALT” + Number to add or remove pencil marks.
Are you new to this Japanese puzzle game?
Basically your target is to fill all blank cells with a number between 1 and 9. In a standard 9 x 9 Sudoku there are basically three constraints you have to follow: Every 3 x 3 block must include all numbers from 1 to 9. Or other way round it should only contain each of these numbers once. The same is required for the rows over 9 cells. Here again each number must be unique and between 1 and 9. And, you can guess, the same applies for the columns. Ready? Ok, let’s start