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 certain numbers filled in, Kakuro puzzles start with each square blank; the 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 Sudoku, logic plays a big role...and there is only one correct solution. The Kakuro Challenge #1 is the first Kakuro book on the market, and contains 201 puzzles ranging from Level 1 ("delicious") to Level 4 ("vicious"), created by puzzle master Alastair Chisholm, author of The Essential Book of Advanced Sudoku #3. His step-by-step guide to playing Kakuro gives you all the directions you'll need...the rest is up to you. But beware: Kakuro is just as addictive as Sudoku, maybe even more so