The popular Japanese puzzle game Sudoku is based on the logical placement of numbers. Sudoku doesn't require any calculation nor special math skills; all that is needed are brains and concentration. Why Do Sudoku? Lots of reasons -Playing Sudoku engages the brain -It can be relaxing, but challenging - you choose the level you want to play at -It increases concentration and focus -For some people it can be as helpful as meditation in improving relaxation and calmness -It improves your logic and memory -Studies have shown that using the brain for puzzles such as Sudoku and Crosswords helps to slow the effects of dementia and alzheimers -You can play a Sudoku puzzle a bit at a time, you don't have to do it all at once, so it's ideal if you're likely to be interrupted The classic symmetrical puzzles of varying difficulty levels. The difficulty level ("Easy," "Medium," "Hard," "Very hard") appears on the printed page along with a difficulty factor ranging between 0.01 and 1.00 (the higher the value, the more difficult the puzzle). - 50 puzzles - Random Difficulty - Solutions included Sudoku is one of the most popular puzzle games of all time.