Kakuro puzzles are a combination of crosswords and sudoku. Whereas in a crossword puzzle the black square represents a block, in kakuro puzzles the black square contains a diagonal line with a number above the line representing the sum (or product) of the numbers across from it and below the diagonal line the number there represents the sum (or product) of the numbers below it. | Kakuro puzzles are a combination of crosswords and sudoku. Whereas in a crossword puzzle the black square represents a block, in kakuro puzzles the black square contains a diagonal line with a number above the line representing the sum (or product) of the numbers across from it and below the diagonal line the number there represents the sum (or product) of the numbers below it. |