Montessori Binomial Cube

Purchased from Monte Mama's Treasures.
This is the Montessori math material "Binomial Cube."
It consists of 8 cubes and rectangular prisms, allowing children to intuitively learn the formula for (a+b)³. In early childhood, it can be played with as a puzzle.
Each individual solid represents an expansion of the formula.
This is the type without a diagram on the sides of the box. The diagram is only on the lid.

There are some minor scratches and stains from use and aging (see photos), but it is still in good condition. I used it with my child a few years ago, but we no longer need it, so I am selling it.

Please consider this item, understanding that it is a used product. Also, please refrain from purchasing if you are sensitive to imperfections, as this is a personal inspection and home storage item.