Matching Dots to Numbers... Place the number tiles in random slots, then match the number of dots on all five intersecting triangles to each tile. All done, right? Not so fast. Now you can build your next challenge — simply swap a few number tiles and the game continues! Remember: a solution is always just around the next twist. With the perfect geometry of an icosahedron, Icosoku can be solved every single try! Icosoku is somewhat like a 3D Sudoku. Designed for Ages 9 to adult, it is completely portable and travel friendly. Solve the evolving challenges...or use as a stimulating fidget toy!