Logic puzzle · Sums and runsKakuro,
Kakuro,
digits that sum.
Fill 1-9 so every run sums to its clue, no digit repeating inside the same run.
- Filled
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- Time
- 0:00
- Hints
- 0
About the gameHow Kakuro works,
How Kakuro works,
in short.
- Step 01
Sums in the black cells.
Each black-and-arrow cell holds the target sum for the run of white cells to its right or below.
- Step 02
Fill digits 1–9.
No digit repeats inside a single run. Use small sums and short runs as your first footholds.
- Step 03
Every run adds up.
Each across run and each down run sums to its clue, with no repeats. Last cell falls into place.
Questions
Kakuro questions, answered.
Kakuro is a sum-based logic puzzle — sometimes called the crossword of numbers. The board is a grid of black blocks and white cells. Each black block facing a row or column of whites carries a clue: the sum the run must add up to. You fill the whites with digits 1 to 9 so each run hits its target, with no digit repeating inside the same run.
Click a white cell to select it. Type a digit 1-9 to place it, or press Backspace to clear. Arrow keys move the selection between white cells. The puzzle is solved when every white cell holds a digit and every run sums correctly to its clue.
Only digits 1 to 9 are allowed in white cells — no zeros. Each "run" is a horizontal or vertical sequence of consecutive white cells. A run's digits must sum to the clue printed in the black cell at its head, and no digit may appear twice in the same run. A digit can repeat across different runs, just not within one.
Easy is a 6×6 board (a 5×5 playable area inside a black border) with short runs — most decisions are forced by combinatorics. Medium is 8×8 with longer runs and more interaction between row and column constraints. Hard is 9×9 with the most chained deductions.
Memorise the forced combinations. A two-cell run summing to 3 must be {1, 2}. A two-cell run summing to 17 must be {8, 9}. A three-cell run summing to 6 is {1, 2, 3}; summing to 24 is {7, 8, 9}. Where a row run and a column run intersect, look for the digit they share. When a run's clue equals the maximum or minimum sum of its length, the digits are completely fixed.
Yes. A fresh puzzle is generated every time you hit New puzzle. There's no daily mode and no streak — solve as many as you like, in whatever order.
Each difficulty has a small set of hand-crafted layouts. When you start a new puzzle the engine picks a layout, fills the white cells with digits respecting the Kakuro constraints via random-order backtracking, and derives the clue sums from the resulting digits.
Yes. Tap a white cell, then tap a digit from the keypad below the board. Tap Clear (or Backspace on a hardware keyboard) to empty a cell.
Tap the cell again, then tap the new digit — or hit Clear to empty it first. Reset on the toolbar wipes every cell so you can re-attempt the same puzzle from scratch.
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