Dominosa Online Free
A full set of dominoes has been laid out and the lines removed. Find where each domino goes so every pair of numbers is used exactly once.
Drag from one number to its neighbour, or tap near the edge between them, to place a domino.
What is Dominosa?
Dominosa is a logic puzzle where a full set of dominoes has been laid out in a rectangle and the lines between them removed. Your job is to split the grid of numbers back into dominoes so that every pair, from 0-0 up to the highest double, appears exactly once.
It needs no arithmetic, only careful tracking of which pairs are still free. Start with the 0–3 set, which has just 10 dominoes, then try 0–5 and the classic double-six set of 28. For another puzzle about splitting a grid into pieces, try Shikaku.
How to play Dominosa
- The grid holds a full set of dominoes. For the 0–6 size that’s every pair from 0-0 to 6-6, 28 dominoes in all.
- Split the whole grid into dominoes, two side-by-side squares each, so that every pair of numbers is used exactly once.
- Drag from a number to the one next to it, or tap near the line between them, to place a domino. Tap it again to remove it.
- A domino turns red when its pair is already used somewhere else. Every puzzle is made fresh and checked to have exactly one solution, so it can always be solved by logic without guessing. Use Hint if you’re stuck, and pick a size at the top of the board.
Dominosa skills
- Systematic checking
- Ruling out possibilities
- Recognising number pairs
Level: Ages 8 and up
Tips for Dominosa
Look for a pair that only appears side by side in one place in the grid. That domino must go there.
A corner square has only two neighbours. If one of those pairs is already placed, the other must be its domino.
Once you place a domino, every other place where that same pair sits next to each other can be ruled out.
Dominosa questions and answers
What is Dominosa?
Dominosa is a domino puzzle game. A complete set of dominoes is laid in a rectangle and the borders are erased, leaving only the numbers. You work out where every domino was.
How many dominoes are in each size?
The 0–3 set has 10 dominoes on a 4 × 5 grid, 0–5 has 21 on a 6 × 7 grid, and 0–6 (the classic double-six set) has 28 on a 7 × 8 grid.
Is Dominosa good for kids?
Yes. The 0–3 size is a gentle start for children around 8. It practises careful checking and ruling things out, the same thinking used to solve math problems step by step.