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Tower of Hanoi Test
A stack of four discs sits on the left rod. Move the whole tower to the right rod, one disc at a time, never placing a larger disc on a smaller one. The fewer moves beyond the optimal 15 and the less time it takes, the better your planning score.
Press Start, then tap a rod to pick a disc up and another rod to drop it.
0moves
A perfect solution for 4 discs uses 15 moves.
About the Tower of Hanoi
The Tower of Hanoi is a classic puzzle invented in 1883 and used ever since to measure executive function and planning. A recursive solution moves a tower of n discs in exactly 2^n − 1 steps, so four discs can never be finished in fewer than 15 moves. Reaching 15 is easy to miss by one careless extra move.
Tap one rod to pick up its top disc, then tap another to drop it. A move is refused if it would put a larger disc on a smaller one, and the timer only starts on your first accepted move. Your grade weighs how close your move count is to the optimum together with how long the puzzle took.
Plan your path in trail making · or stretch your working memory with mental math