**Sudoku **game with thousands of different puzzles, from very-easy to super-hard!

Sudoku is sometimes incorrectly spelled as suduku, suduko, sudoko, soduku, soduko, sodoku, sodoko.

**Su Do Ku**,
"single number", Japanese skill and mind game which is a logic-based
number placement puzzle. The objective is to fill a 9×9 grid so that
each column, each row, and each of the nine 3×3 boxes (also called
blocks or regions) contains the digits from 1 to 9, only *one* time each (that is, exclusively).