Have an uncanny intellect and a love of logic? Why not try this challenging logic number game that is harder than Sudoku and just as engaging? These 120 15 x 11 puzzles can keep your mind sharp and your spirits bright. Take the challenge and master the ancient art of cross sums. A Kakuro puzzle is constructed on a crossword grid just like a crossword puzzle, but instead of letters, the digits 1 to 9 are used. In a standard Kakuro puzzle, the Across and Down clues are simply the sums of the digits in the across and down slots. Kakuro has one other rule: the same digit cannot be repeated within any run. You can, however, repeat a number elsewhere in the same row or column of the puzzle so long as there is at least one non-solution square between them - or in other words, so long as it is in the solution to a different clue.