Free games › Mental Rotation › How a solver cracks it
How a solver cracks mental rotation puzzles
Mental Rotation asks which figures are the target turned, and which are its mirror image. A solver does not picture anything: it uses a fact about shapes.
The method
- List the 24 ways to turn a cube. Turning a solid object in space has exactly 24 distinct orientations. A mirror image is not among them.
- Turn the target through all 24. For each, slide the shape to a standard corner and write down its cube positions in order, so two shapes that coincide give the same list.
- Compare. An option is "the same object" only if its list matches one of the 24. If none match, it is a mirror image: it has the same arm lengths and the same angles, but no turn will ever bring it onto the target.
What a person can borrow
Handedness never changes under rotation. Follow the longest arm, then ask which way the next arm bends off it; that one feature separates a turned figure from a mirrored one.
- Free to play
- No sign-up to start
- Coaching built in
- Play with friends in groups