Sudoku is a puzzle game played on a 9 x 9 grid. There are 9 "squares" (consisting of 3 x 3 spaces) in the rows and columns. In each row, column, and square (9 spaces each) you should enter numbers 1-9, without repeating any numbers in the row, column, or square. Does that sound complicated? As you can see in the image below of an actual.
As you can see, in the top left square (circled in blue) this field has 7 out of 9 fields already filled. The only numbers that are missing from the square are 5 and 6. Seeing which numbers are missing in each square, row or column, we can use the process of elimination and deductive inference to decide which numbers to put in each blank.
For example, in the top left square, we know we need to add 5 and 6 to be able to complete the square, but from the adjacent rows and squares, we cannot infer which number to add at what point. This means that we should ignore the top left square for now and try to fill in spaces in other areas of the grid instead.
Now that you know how to play Sudoku, why don’t you give it a try?