Cylinders
Five cylinders, five holes, and only one way everything fits.
Free
What it is
One of the oldest pieces of Montessori equipment, and still one of the best. A wooden block has five holes of different sizes; five cylinders sit below it, and each belongs in exactly one.
Every round arranges them differently, so the solution can't be memorised — it has to be worked out by looking.
How to play
Drag a cylinder towards a hole. If it is the right one it drops in with a wooden knock. If not, it returns to the table.
The round finishes when all five are seated. There is no timer and no score.
What it builds
Montessori called this the control of error: the material itself tells the child whether they were right, without an adult saying anything. A cylinder either fits or it doesn't.
What it trains is visual discrimination of size — noticing that two things which look similar are not the same. That skill underpins a surprising amount of later maths.
Ages and pace
Around two and a half to three. Younger children tend to try every cylinder in every hole, which is a perfectly valid method and how the discrimination gets learned.
This game is free. A one-time purchase opens the ones that are not, and there is no subscription.
No ads. No data collected. Works offline.