How do you work the Sudoku puzzle?!
Question:
How do you work the Sudoku puzzle?
Answers:
You must use each of the digits 1-9 only once in each space across in each row and in each space down in each column. Also you must use each of the digits 1-9 only once in each space in the 9 3x3 grids.
Some numbers are prefilled and therefore you can deduce what goes in many other squares. In the harder ones you finally get to a point where you have to guess and see where it leads you. When you get stuck you have to back out moves.