Kakuro
Play Kakuro free online: fill grid runs with unique digits 1-9 that sum to the clue numbers. A crossword-style math puzzle with Retro Coins.
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How it works
Play, earn points and Retro Coins: the shared currency across every RetroPlayNow game. Unlock badges and climb the leaderboard! Your progress is saved automatically on this device.
Kakuro, sometimes called Cross Sums, is the arithmetic cousin of the crossword. Instead of words, you fill the grid with digits 1 through 9. Instead of definitions, each horizontal and vertical run of white cells has a clue number that the digits in that run must sum to. And like sudoku, no digit may repeat within a single run.
The beauty of Kakuro lies in the combination constraints. A run of two cells summing to 17 can only be 8+9 (since 9+8 is the same pair). A run of three cells summing to 6 can only be 1+2+3. These forced combinations are the building blocks of every solution.
As you advance, the puzzles become intricate webs of intersecting runs. A single cell belongs to one horizontal and one vertical run simultaneously. Finding a cell where both constraints converge to a single digit is the key to unlocking the puzzle.
Our RetroPlayNow version offers hand-crafted puzzles at multiple difficulty levels, a candidate-pencil mode for noting possible digits, error highlighting for conflicts, and a library of combination hints for beginners. Every completed puzzle earns Retro Coins.
How to play Kakuro
- Fill runs with unique digits. Each horizontal and vertical run of white cells must be filled with digits 1-9, no repeats within a run.
- Match the clue sums. The digits in each run must sum to the clue number shown at the start of that run.
- Use combination logic. Some sums have only one possible combination of digits. A two-cell run summing to 17 must be 8+9. Learn these patterns.
- Find intersection cells. Cells that belong to both a horizontal and vertical run are the most constrained — solve them first.
- Earn Retro Coins. Complete puzzles to score points based on difficulty and solving time. Faster solutions earn more Retro Coins.
