Brown Stair
Ten brown prisms, each 20 cm long with square ends from 1 cm to 10 cm, make the brown stair, also called the broad stair. Children of 2.5 to 4.5 lay them side by side from thickest to thinnest. On October 2, 2026, three US sellers had it for $88.20 to $203.35; we'd buy rather than cut it.
The first lesson with it is Brown Stair (Broad Stair). Not sure your child is ready for it? Two minutes of questions place your child on the sequence.
| Area | Sensorial |
|---|---|
| Used in | |
| From age | 2.5 to 4.5 years |
| Make it | Hard to make accurately |
| Buy it | About $88 to $203 (noted ) |
What the brown stair is for
The pink tower changes in three dimensions; the stair changes in two. Every prism is 20 cm long, and only the square end grows, 1 cm at a time. Montessori's 1912 prisms were stained dark brown, and her 1914 Handbook has the child scatter them over a light-colored carpet.
Each end matches the pink tower cube of the same number, so the two are often bought together. Like the tower, the stair has no built-in check. A mistake shows as a high step with a drop behind it, and only the eye catches it.
| Part | What it looks like |
|---|---|
| Prisms | Ten, all 20 cm long |
| Ends | Square, 1 by 1 cm up to 10 by 10 cm |
| Thickest prism | 10 by 10 by 20 cm, 2,000 cubic centimetres of solid wood |
| Finish | Brown stain or brown lacquer |
| Spare | Montessori Outlet adds a second 1 by 1 by 20 cm prism |
The lessons that use the brown stair
Brown Stair (Broad Stair)
2.5 to 4.5 yearsArranging ten brown prisms, all the same length but growing in thickness, into a stair from thickest to thinnest.
Buying one: 3 listings checked October 2, 2026
| Seller and set | Made of | Price |
|---|---|---|
| Alison's MontessoriBrown Stair (S02)Sale price; regular $98.00. Made in Thailand. | Hardwood, brown lacquer | $88.20 |
| Montessori OutletBrown Stair (Brown Lacquer) (510300091)Includes a spare 1 by 1 by 20 cm prism. Market price shown $199.35. In stock. | Hardwood, brown lacquer | $99.95 |
| NienhuisThe Brown Stair (Brown Lacquer) (002550)1 by 1 by 20 cm to 10 by 10 by 20 cm. US store price. | Beech | $203.35 |
- We'd buy it. Ten prisms have to be cut square along their whole length, and the thick ones are big solid blocks. If the 10 cm prism comes out 9.6 cm, the step down to the 9 cm prism shrinks to 6 mm and the stair looks wrong where it's right.
- Buy it with the pink tower if the budget allows. The ends match the cubes, and later work puts the two together.
- The $115.15 between the cheapest and dearest set buys beech and Nienhuis's finish; all three list the same sizes. The Montessori Room's stair was sold out and Kid Advance's page would not load for us.
Keeping a full set on the shelf
- Store the stair on the lowest shelf, thickest prism at the bottom or the back, so the child starts from a finished stair.
- Carry one prism at a time, the thick ones in two hands. The 10 cm prism hurts if it lands on a foot.
- Run a hand along the long edges now and then. A dented corner makes two prisms sit unevenly and hides the step.
Questions parents ask about the brown stair
Is the broad stair the same as the brown stair?
Yes. Broad stair is the name in Montessori's 1914 Handbook, and brown stair is what most catalogs call it now. Her 1912 book calls it the big stair.
Should the brown stair come before or after the pink tower?
After, in most sequences. The tower varies in three dimensions and the stair in two, and the Handbook lists the cubes first, then the prisms, then the long rods.
What does the brown stair teach?
Thick and thin, judged by eye, with the length held constant so thickness is the only thing that changes. Later it carries the words thick and thin, and after that thickest and thinnest.
Before the brown stair, make sure the work before it is solid. The pink tower lesson lists the signs that a child is ready to move on.