Geometric Stacker by Melissa & Doug is a toy that is entertaining Max for hours. It is quite a step up from the basic ring stacker. The stacker has a trick under its sleeve. You can play Towers of Hanoi with it:
At the start, all the disks are in the leftmost stack, with the largest disk on the bottom and the smallest on the top. The object is to get all the disks over to the rightmost stack. You can only move one disk per move, and you can only move the top disk on a stack. The top disk of any stack can be moved to the top disk of any other stack, with the restriction that you can’t move a larger disk on top of a smaller disk — i.e., disks can only be moved to empty stacks or on top of larger disks. You start with just a few discs and add extra disc if it gets too easy.
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