(Never be afraid to ask!)
One parent recently confessed that although her two children had gone through the Montessori school curriculum from the toddler and preschool levels (Children’s House) through grade 8, she’d never understood how the Pink Tower worked. Or the Brown Stairs. The Binomial Cube was another mystery, as she’d seen it referenced in math progress reports but had never actually seen one in action.
Here at Inly Insights we’ll shed some light on a handful of these classic materials, explaining both the direct and indirect purpose of each and how they all tie together in the continuum. If there’s anything you’d like to see in a future spotlight, please drop us a line!

The Pink Tower: A Montessori Preschool Staple
The iconic Pink Tower, designed by Dr. Maria Montessori herself, remains a fixture in Montessori classrooms around the world. How does it work, and what is its purpose?
How it works:
Children are introduced to the series of 10 graduated wooden cubes. The smallest is 1 cubic cm and the largest is 1000 cubic cm. (They get larger by 1cm cubed up to the largest block, which is 10cm cubed.)
The teacher presents the work, building up the 10 cubes in the correct order while explaining the movements and sequence. Children then do the work themselves, independently. This is a self-correcting work — meaning the cubes have to be assembled correctly to construct the tower. Putting the correct cube neatly on top of the other requires skill and concentration!
Children take turns doing this work independently. They move the first (smallest) 4 cubes using one hand, and the rest using two hands.
Did you know?
You’d need 1,000 of the smallest cubes to equal the biggest cube in the tower.
The purpose of the work:
The Pink Tower teaches the relationship between size and weight while refining motor skills. Children absorb pre-math concepts as they spatially see the mathematical relationship of the blocks. Sequencing the blocks begins math sequencing skills. The structure spurs children to organize their thinking, problem-solve in a clear way, and absorb the learning lesson of the materials. It is sensorial work, which helps children classify and understand the world around them.

What does a child learn?
- Size, weight and spatial awareness— The Pink Tower helps build the concept of size in three dimensions. Sensorial work involving visual perception and awareness of dimension leads to an understanding of size in the greater environment.
- Fine motor skills and hand-eye coordination— It helps develop a child’s muscle fine-motor skills and hand-eye coordination, as well as coordination of movement. The three-finger grasp develops hand-writing muscles while the precise work hones focus and concentration.
- Abstract math concepts– It prepares children for abstract mathematical concepts, such as spatial volume and the cube root. It indirectly introduces the Decimal System, as the child works with 10 cubes which represents the numbers 1-10. It also introduces Geometry, as the child explores the different cubes and develops visual discrimination of dimensions.
- Language skills – It encourages children to describe comparative size (small, smaller, large, larger, bigger, biggest) while working with integrated language lessons. It also prepares the hand muscles for writing, as children need to use the 3-finger grip to carry the cubes.
Why is the Pink Tower pink?
While experimenting with different colors, Dr. Maria Montessori observed that children were more attracted to pink, compared to others. As with all of her work, she let research be her guide.
What are Montessori Sensorial Materials?
Montessori sensorial materials are used in the classroom to help children develop and refine their five senses.
Like many other materials in the Montessori classroom, sensorial materials have “control of error” — meaning the child has a way to check their work rather than seeking out the teacher if they question whether or not they did it right. This is done to help promote independence and problem-solving from a young age. This type of “self-correcting” or “auto-instructional” material allows children to discover, practice and master their work, with deepens the learning experience.
These sensory-based learning materials are also uniquely designed to isolate one skill or concept at a time. This helps the child absorb clear information which can then be built upon in layers. Through hands-on work with Sensorial material, children gain knowledge not only through direct instruction, but through their own tactile experiences as well. This provides a foundation for experiential learning at all grade levels in a Montessori education.
Its very true that children at this age is sensorial explorers and only by observing the environment the intelligents create.