Kakuro is like a crossword puzzle with numbers. Each “word” must add up to the number provided in the clue above it or to the left. Words can only use the numbers 1 through 9, and a given number can only be used once in a word. Every kakuro has one and only solution, and can be solved through logic alone. To see step-by-step how a kakuro is solved, you might want to look at a basic kakuro tutorial or a challenging kakuro tutorial.