Number Slide Puzzle – Free Online Game
Classic sliding tile puzzle in multiple sizes. Arrange the numbered tiles in order by sliding them into the empty space.
Grid sizes
- 3×3 (8 tiles) — easy; solvable in a couple of minutes once the method clicks
- 4×4 (15 tiles) — medium; the classic version, and a genuine step up
- 5×5 (24 tiles) — hard; the same technique, with much more of it
The method that actually works
Most people fail by trying to place tiles wherever they happen to be near. The reliable approach is to solve it in layers and never disturb what is finished.
- Complete the top row, left to right, then treat it as off limits
- Complete the left column of what remains, then leave that alone too
- Repeat on the smaller square that is left
- When only a 2×2 remains, rotate the three loose tiles until they land
The last tile in a row is the awkward one. Place it below its target rather than beside it, then rotate the pair into position together — trying to slide it in directly is what breaks the row you just built.
Why it is a good classroom puzzle
It rewards planning several moves ahead and punishes guessing, but the rules take ten seconds to explain and there is no reading load. The 3×3 works for younger students; the 4×4 will occupy most adults for a while.
If you want more puzzles in the same vein, try Sudoku for logic, Tile Fitter for spatial fitting, or Treasure Hunt for deduction from hints.