Kakuro are language-free number puzzles that use pure logic and require just simple arithmetic to solve. This book contains 150 kakuros. It takes cue from the belt colors in martial white is for novices, green for intermediates, brown for very accomplished players, and black for those consummate experts who crave a challenge.
Since this is the first level in this series, I would have expected a bit more introduction and guidance. But being puzzles, the main attraction is of course in finding out these things on you own. While I found some puzzles to really stand out, most of them follow a pattern of progressively more complex toward the end of the book.