Kakuro is sometimes described as a "number crossword" or "mathematical crossword," and indeed the puzzle grids resemble those of crossword puzzles. In contrast to Sudoku, where you start with each square blank; clues to filling them in are in the horizontal and vertical totals given for each row and column, and in "Kakuro blocks," combinations of the only numbers that will match certain totals. Just as in Dudoku, logic plays a big role....and there is only one correct solution.

The Kakuro Challenge 1 2005, Walker Books, New York

ISBN-13: 9780802715289

Trade paperback