With a separate sudoku book for every level, all puzzle lovers can play
this wildly popular, incredibly addictive game thats appearing in major
newspapers all over! Taking a page from karate--another Japanese
art--each title is graded by color: White Belt for easy, Green Belt for
medium level, Brown Belt for hard, and Black Belt for the super-tough
solvers. And because each book has an amazing 300 puzzles, the fun can
go on for hours.