Trinomial Cube
The trinomial cube is a hinged wooden box of 27 painted blocks, three colored cubes and 24 prisms, used as a building puzzle from about 4 and for algebra years later. It costs $39.95 to $210.60 at the US sellers we checked on October 5, 2026. Buy it; the blocks need exact cuts.
The first lesson with it is Trinomial Cube. Not sure your child is ready for it? Two minutes of questions place your child on the sequence.
| Area | Sensorial |
|---|---|
| Used in | |
| From age | 4 to 6 years |
| Make it | Better bought than made |
| Buy it | About $40 to $211 (noted ) |
What the trinomial cube is for
The 27 blocks are the parts of (a + b + c)³ cut apart. There are three cubes, one for each term, each in its own color. The prisms have black sides and colored ends, and six are black all over. The child rebuilds the cube in three layers of nine.
Montessori's 1917 book has only the binomial version, for older children studying the powers of numbers. The trinomial cube, and its use as a puzzle for 4 year olds, comes from the later albums.
| Part | What it looks like |
|---|---|
| Cubes | Three: red, blue and yellow, in three sizes |
| Prisms with colored ends | Eighteen, with black sides and two red, blue or yellow square ends |
| All-black prisms | Six |
| Box | Hinged sides and the top layer's pattern on the lid. Alison's is 4.25 by 4.25 by 4 inches |
The lessons that use the trinomial cube
Trinomial Cube
4 to 6 yearsTaking apart and rebuilding a cube of 27 blocks in three colors, layer by layer, the harder sequel to the binomial cube.
Buying one: 4 listings checked October 5, 2026
| Seller and set | Made of | Price |
|---|---|---|
| Montessori OutletTrinomial Cube (510500520)27 painted wooden pieces in a hinged box with the pattern printed on the lid. Market price shown $206.45. In stock. | Not stated | $39.95 |
| Alison's MontessoriTrinomial Cube (M07)Sale price; regular $90.00. 27 pieces; the box opens out flat; pattern on the lid. 4.25 by 4.25 by 4 inches. Made in Thailand. | Wood, painted red, black, blue and yellow | $81.00 |
| NienhuisTrinomial Cube (013200)US store price. Ages listed as 3 to 4 years. The page doesn't state the piece count. | Birch plywood, beech plywood, metal | $210.60 |
| The Montessori RoomTrinomial Cube (A161)Canadian store. Sold as a budget version: 27 painted pieces in a hinged box. Ages 4.5 and up. | Beech and MDF | $64.99 CAD |
- Montessori Outlet's $39.95 cube and Nienhuis's $210.60 cube do the same job for a 4-year-old. What matters is that the lid closes with all 27 blocks in place.
- Buy from the same maker as your binomial cube if you can, so the colors match and the red and blue blocks look alike in both.
- The algebra use years later needs the same 27 blocks, not a better finish.
- Montessori Services sells a trinomial carpet but no cube, so it isn't in the table.
Keeping a full set on the shelf
- Count 27 blocks back into the box after every turn. The yellow cube is the smallest piece and the first to go missing.
- Wipe with a barely damp cloth. Chipped paint on a colored end makes it hard to match, so touch it up.
Questions parents ask about the trinomial cube
How many pieces are in a trinomial cube?
Twenty-seven: three colored cubes, eighteen prisms with black sides and colored ends, and six prisms that are black all over.
Do I need the binomial cube first?
Yes. The binomial cube's eight blocks teach the idea in two colors. The trinomial cube adds a third color and a third layer, and a child who meets it first usually gives up.
Can I make a trinomial cube?
We wouldn't. Twenty-seven blocks in three sizes must fit a box with no gaps. Sets start at $39.95 in our table.
Before the trinomial cube, make sure the work before it is solid. The binomial cube lesson lists the signs that a child is ready to move on.