🔢 Kakuro
🧩 Logic · 2 playsKakuro
A crossword built out of sums: fill each run with digits that reach its total.
About Kakuro
Kakuro has the shape of a crossword and the substance of arithmetic. Each run of white cells, across or down, carries a target in the shaded cell at its head, and must be filled with digits from 1 to 9 that add to that target without any digit repeating inside the run. The constraint bites harder than it looks: a run of two totalling 17 can only be 8 and 9, and a run of three totalling 6 can only be 1, 2 and 3. Knowing those forced combinations is most of the puzzle. The rest is finding where an across run and a down run can only agree on one digit.
How to Play
Tap a white cell and enter a digit from 1 to 9. Every run must add up to the clue printed in the shaded cell at its head. No digit may appear twice within the same run. Begin with the runs that allow only one combination.
💡 Tips & Strategy
Learn the sums with only one possible combination and half the grid unlocks itself. In two cells: 3 is 1+2, 4 is 1+3, 16 is 7+9, 17 is 8+9. In three: 6 is 1+2+3, 7 is 1+2+4, 23 is 6+8+9, 24 is 7+8+9. In four: 10 is 1+2+3+4 and 30 is 6+7+8+9. Any run carrying one of these has a fixed set of digits even before you know their order.
The real leverage comes from intersections. A cell sits in both an across run and a down run, so it must belong to both of their digit sets. Write out the two candidate sets and take the overlap — frequently one digit survives, and each placement narrows the runs that cross it.
When no unique combination applies, bound the cells instead. A five-cell run summing to 20 cannot contain a 9, because the smallest four other digits already total 10. Working out the maximum and minimum a cell can hold eliminates candidates fast and needs no memorisation.
Remember the no-repeat rule applies within a run, not across the whole line. Two separate runs in the same row may happily both contain a 4, and solvers who forget this talk themselves out of correct placements.