This sensorial lesson is designed for 3 to 6-year-old children to guide them with the difference in diameter and height using Montessori green knobless cylinders.

In our previous video, we learned about the Montessori yellow knobless cylinder box. It teaches the child how a cylinder’s height and size decrease when placed in a row.

## What are Green Knobless Cylinders?

The green knobless cylinders box is a set of 10 green-colored knobless cylinders and is 3rd in the row when introducing Montessori knobless cylinders to the child. In this box, as the diameter of the cylinders decreases, the height increases.

It is introduced to develop visual discrimination based on the difference in diameter and height.

## Purpose of Introducing Green Knobless Cylinders

• It helps in developing a child’s visual perception of dimension.
• It helps in developing a child’s order and coordination.
• It improves movement and fine motor control.
• It helps the child prepare for more complex topics in mathematics such as comparison, grading, and seriation with varying combinations of other 3 knobless cylinders.

## Control of Error

Each cylinder has a different diameter and height when seen visually.

## Points of Interest

• The color of the cylinders, i.e. green.
• The difference in the size and height of each cylinder.

## How to Present Montessori Green Knobless Cylinders to the Child?

1. Invite the child to the table while carrying the box of green knobless cylinders.
2. Take off the box lid and place it below the box.
3. Using your thumb and two primary fingers, slowly remove each cylinder and place them randomly in a row in front of the child.
4. Tell the child “Now, I am going to arrange these cylinders in order.”
5. Introduce the child with the thicker and thinner green cylinders.
6. Let the child compare its size.
7. Now, place the thicker green cylinder on the left.
8. Select the next longest green cylinder and place it in position 2 (from left to right.)
9. Continue till all the cylinders are placed in order from thickest to thinnest.
10. Touch the top of each cylinder from left to right and introduce them again with the concept of thickest to the thinnest.
11. Ask the child, “Do you observe any difference in these cylinders?”
12. Let them reply, “Yes, as we move from left to right, the height of the cylinder is increasing. They are becoming taller”.
13. Agree with them and say, “yes, these cylinders are increasing in height but their diameter is getting smaller as we are moving from left to right.”

Invite the child to arrange the cylinders as per the size as shown in the video and help them develop their visual dimension senses.