Number Jigsaw — Sum-to-10 Edge-Matching Puzzle
Number Jigsaw is an edge-matching puzzle with a twist: every tile has a number on each of its four sides, and touching edges must add up to ten — not just match. A 7 needs a 3, a 4 needs a 6, a 5 needs a 5. Every edge that faces the outer border must show zero. Pick a grid size from 3×3 to 6×6 and a difficulty, and a fresh puzzle is generated instantly — there's no fixed level list, so you can keep playing indefinitely.
How to Play
Select a Piece
Tap a tile in the tray below the board to select it. Its border highlights blue while selected.
Rotate It
Use the Rotate button to spin the selected tile 90° at a time until the numbers line up the way you expect.
Place It
Tap an empty board cell to drop the tile there. Edges that add up to 10 turn green; edges that don't, or non-zero edges facing the border, turn red.
Fix Mistakes
Click a placed tile to rotate it in place, or long-press (right-click on desktop) to send it back to the tray.
Game Features
- 🎲 Unlimited Puzzles. Every game is freshly generated — choose a 3×3 through 6×6 grid and one of four difficulties, any time.
- ✅ Live Validation. Every touching edge is checked in real time, so you always know which placements sum correctly.
- 💡 Hint System. Stuck? A hint reveals the next correct placement for one tile.
- ↩ Undo & Restart. Step back through every placement and rotation, or reset the puzzle entirely.
- 💾 Auto-Save. Your progress is saved automatically per grid size, so refreshing mid-solve never costs you your work.
Frequently Asked Questions
Why do the edges need to add up to 10, not just match?
That's the core twist of Number Jigsaw. A tile showing 7 must touch a tile showing 3, a 4 must touch a 6, and a 5 must touch a 5 — plain equal-number matching is not enough.
What do the numbers on the border mean?
A zero edge must always face the outer border of the board. If a zero edge touches another tile instead, that side turns red — rotate or move the tile until every zero faces outward.
Is every puzzle solvable?
Yes. Each puzzle is generated from a fully solved grid where every interior edge is already paired to sum to 10, then cut into tiles and shuffled — so a valid solution always exists.
How does difficulty work if the grid always sums to 10?
Higher difficulties draw edge numbers from a narrower range (e.g. Expert only uses 4, 5, and 6), which makes far more tiles look like they could fit — even though only one placement is correct.
How are stars calculated?
Solving a puzzle in exactly one placement per tile, with no hints used, earns 3 stars. Extra moves or hints lower your rating to 2 or 1 star.
Is my progress saved?
Yes. Your in-progress board and your best move count and time for each grid size are saved to your browser automatically.
Can I play on mobile?
Yes. Tap to select, rotate, and place tiles; long-press a placed tile to send it back to the tray.