The Brown Stair
COMPONENTS: • 10 wooden prisms • Length: 20 cm • Width: 1 cm to 10 cm square (All the same length but graduated height and width) | DESCRIPTION: • Montessori Sensorial Material • Auto-correcting • Blocks vary in two dimensions |
MATH SKILLS DEVELOPED: • Sequencing • Counting numbers 1–10 • Relationship of square numbers 1–10 | DO THE MATH: • 4 of the smallest prism = the second stair • 9 of the smallest prism = the third stair • 100 of the smallest prism = the last stair |
LEARNING APPROACHES: • Visual • Tactile, Kinesthetic • Logical-Mathematical | OFTEN USED WITH: The Pink Tower – as an extension activity |
How It Works
The Brown Stair (also called Broad Stair) is made up of ten wooden prisms. While the prisms are all the same length (20 cm), they vary in thickness from 1 to 10 cm. When put together from thickest to thinnest, they make an even staircase.

This classic Montessori material is an important pre-math “work” designed for preschool students age 3 and up. Working with this tactile, hands-on material, children refine muscular coordination, fine motor control and the ability to discriminate differences in size and weight. They learn about patterns, proportions and distances and develop the language to describe them. Similar to the Pink Tower, the Brown Stair is an important basic material in both early mathematics and sensory training.
The Purpose and Learning Objectives of the Work
Designed to vary in only two dimensions, the Brown Stair work promotes:
1) Visual perception and muscular feel of differences in size
2) Understanding and awareness of dimensions and spatial location
3) Math readiness: Prepares for geometry and concept of numbers

It also reinforces the numbers work done throughout the Montessori preschool and kindergarten curriculum by demonstrating:
- Sequencing
- Continued emphasis on 1 through 10
- The stress on 10 in different contexts
- The relationship and difference between the squares of the numbers 1 to 10
In Montessori schools, all of this work is purposefully designed to develop and engage the “mathematical mind.”
Preschool Language Development
Vocabulary: Thick and thin, greater and smaller, heavier and lighter
Children use everyday words to describe size and position while also exploring shape, form and space in two or three dimensions. They recognize, create and describe patterns and learn to use mathematical language to describe them.
Did you know?
The height and width of the Brown Stair matches the height and width of the Pink Tower, allowing the two materials to be used together to create interesting and thought-provoking extensions. Children find it fascinating to explore the interrelationships of the pieces and to design combinations of their own.
Cool Montessori Activity!
(There’s an app for that?) Check out this demo of a Brown Stair & Pink Tower extension activity that teachers use to help prepare Montessori preschool students for math.
Read more about Montessori Preschool Materials and the Benefits of Montessori Education:
Inly Insights: Everything You Ever Wondered About Montessori Materials
So cool!