What is the brown stair in Montessori?
The brown stair (broad stair) is a sensorial material of ten brown wooden prisms, all 20 cm long, with square cross-sections increasing from 1 cm to 10 cm. Children arrange them from thickest to thinnest, learning to see differences in thickness, a two-dimensional change, unlike the pink tower's three-dimensional change in size.
What this means in practice
The brown stair is often presented after the pink tower, and the two are later combined.
Purpose
- Visual discrimination of thickness
- Vocabulary: thick, thicker, thickest; thin, thinner, thinnest
- Muscular sense through carrying
- Preparation for later maths work
Extensions
Build with gaps, combine with the pink tower (the cube matches the prism's end), and play memory games across the room.
Practical next steps
- Present after the pink tower.
- Use precise vocabulary.
- Invite extensions.
- Observe self-correction.
ExampleAfter the brown stair, Jamal discovers the 10 cm cube of the pink tower fits exactly on the end of the thickest prism.
What to keep in mind
Handle prisms carefully; corners chip easily.
Common follow-up questions
What is the dimension?
Length 20 cm; sections 1–10 cm square.
Is it the broad stair?
Yes, another name.
Sources
Examples are educational illustrations with made-up names. How these answers are prepared.