At home, even as commuting, all over lunch hours…people around the globe are eagerly working on Sudoku puzzles whenever and wherever they are able to!
Created in the US, these intriguing conundrums were originally known as Number Place puzzles. Their up to date rise in popularity began in Japan, where the name translated as sudoku. Here we’ve indicated the skill level necessary to complete each sudoku book in this series in the same way Japanese karate levels are ranked: by different colored belts. This is the Black Belt volume, filled with puzzles if you want to provide a sly, absorbing test for even the most efficient, most proficient experts.
It’s not possible to complete only one sudoku at a time, because solving them is habit-forming!