Kakuro has become the new puzzle phenomenon gathering millions of fans worldwide. Older than Sudoku and played for many years in Japan, Kakuro is best described as a kind of mathematical crossword. The Guardian Book of Kakuro will feature over 100 different puzzles, (of varying degrees of difficulty). Each puzzle has been hand crafted by a Japanese inventor and is wholly original. The Guardian Book of Kakuro will also include four pages of 'How To' explaining the rules and featuring example puzzles, plus a page of unique number combinations (saving the need to constantly add up!).