A fun hobby that exercises your brain and gives you a sense of accomplishment. That's the perfect description of the numbers puzzle from Japan called sudoku.
* Sudoku 9x9 - Very Easy to Extreme is a collection of 300+ puzzles with solutions:
* 56 Very Easy Sudoku 9x9 puzzles
* 56 Easy Sudoku 9x9 puzzles
* 56 Normal Sudoku 9x9 puzzles
* 56 Hard Sudoku 9x9 puzzles
* 56 Very hard Sudoku 9x9 puzzles
* 56 Extreme Sudoku...