Fill empty squares so each block adds up to the number on its left or its top The object is to fill all empty squares using numbers 1 to 9 so the sum of each horizontal block equals the clue on its left, and the sum of each vertical block equals the clue on its top. In addition, no number may be used in the same block more than once. There is only one unique solution for each puzzle. Got all that? Are you ready to give it a go? Good, because you’re going to have a very good time playing Kakuro Light Vol 1!