Kakuro

About Kakuro

Kakuro is the cross sum puzzle: a crossword made of numbers. Every run of white squares has a total printed in the black square at its start, and you fill it with different digits from 1 to 9 that add up to that total, across and down at once. The sums are small; the fun is in the logic, because a short run with a very small or very large total can only be made one way, and that fixes the squares around it. Every daily grid has one solution and needs no guessing.

How to play Kakuro

1. Each black square holds a clue: the number above its diagonal is the sum of the white run to its right, the number below is the sum of the run beneath it.
2. Fill every white square with a digit from 1 to 9. The digits of a run must add up to its clue, and no digit may appear twice in the same run.
3. Select a square, then type a digit or tap the number pad. Notes add pencil marks; the helper lists the digit sets for the selected runs.
4. Easy grids are 6 × 6, medium 8 × 8 and hard 10 × 10. Every grid has one solution and can be solved by logic alone. Fastest time wins.

Tips & strategy

• Start with the runs that can only be made one way: 3 in two squares is 1 and 2, 17 in two is 8 and 9, 24 in three is 7, 8 and 9.
• Where an across run and a down run cross, the square takes a digit both runs allow; comparing the two often leaves one.
• The possible digits helper lists every set that makes the selected runs, narrowed by the digits already placed.
• Use notes for squares with two or three candidates; no digit can repeat inside a run.

Kakuro: questions and answers