Sudoku requires no calculation or arithmetic skills. It is essentially a game of placing numbers in squares, using very simple rules of logic and deduction.

The objective of the game is to fill all the blank squares in a game with the correct numbers. There are three very simple constraints to follow. In a 9 by 9 square Sudoku game:
1) Every row of 9 numbers must include all digits 1 through 9 in any order;
2) Every column of 9 numbers must include all digits 1 through 9 in any order;
3) Every 3 by 3 subsection of the 9 by 9 square must include all digits 1 through 9.

Every Sudoku game begins with a number of squares already filled in, and the difficulty of each game is largely a function of how many squares are filled in. The more squares that are known, the easier it is to figure out which numbers go in the open squares. As you fill in squares correctly, options for the remaining squares are narrowed and it becomes easier to fill them in. More detailed instructions are at Sudoku Anyone????.