Ten wooden cubes painted pink and varying from 1 x 1 x 1cm to 10 x 10 x 10cm, including one spare 1x1x1 cube.
" Montessori Pink Tower differs in 3 dimensions" - Maria Montessori.
The work is designed to provide the child with a concept of "big" and "small."
The child starts with the largest cube and puts the second-largest cube on top of it. This continues until all ten cubes are stacked on top of each other.
The control of error is visual. The child sees the cubes are in the wrong order and knows that they should fix them.
The successive dimensions of each cube are such that if the cubes are stacked flush with a corner, the smallest cube may be fit squarely on the ledge of each level.