# Geometry Cabinet

Discover how two dimensional shapes are introduced.

Geometry is a subset of mathematics that deals with the shapes of objects, including size, shapes, angles, and dimensions. It is one of the oldest branches of math because it helps to describe the shapes we see all around us!

To prepare children for future work with geometry, we present them with the geometry cabinet, which introduces the child to over 40 different shapes. This cabinet contains six drawers, each holding wooden shapes the child can feel, hold, and manipulate so that he or she can learn to distinguish between the different shapes. The various figures are grouped by similar shapes: Circles, Rectangles, Triangles (there are seven types!), Quadrilaterals (such as a rhombus and a parallelogram), Curved figures (including an oval and an ellipse), and Regular Polygons (such as pentagons and hexagons).

At school, we introduce your children to the cabinet and invite them to explore through lots of hands-on experiences. They trace the shapes, play games with them, and search the classroom for their favorite shapes too. Later we give children the language of the shapes using the three-period lesson.

## Three Period Lessons

Three-period lessons are the primary way Montessori teachers introduce children to new vocabulary. These lessons are given every day in the primary classroom. They are quick, simple, fun! And follow a simple formula that I will share with you today.

But first, allow me to share a bit of history. Three-period lessons were originally developed by the French physician Edouard Seguin. Seguin was a psychiatrist who developed methods for helping children with learning differences more easily associate objects and their names. Dr. Montessori was inspired by his work and adopted his approach for her classrooms. Fun fact: Edouard Seguin also developed the geometry cabinet!

#### The Three Period Lesson is comprised of three different stages:

1. Introduction
2. Practice with Recognition
3. The “Test”

To better illustrate the lessons, we can use the presentation tray of the geometry cabinet as an example. We use this tray to introduce the youngest of primary children to the names triangle, circle, and square.

#### 1st Period: Introduction

We begin by picking up the shape and giving its precise name of the shape, repeating for emphasis:

“This is a square. Square; This is a circle. Circle; This is a triangle. Triangle.”

#### 2nd Period: Recognition

This phase helps the child recognize the shape by name when it is given. Starting with the last object introduced, we use active commands that require the child to physically manipulate the objects as a way to reinforce their association between the name and the shape.

“Touch the triangle. Pick up the circle. Hand me the square. Put the circle at the top of the table.”

Your children are smart, so after a few commands, rotate the order of the objects before continuing. Be careful not to use your eyes to give the child clues as you work through the second period. The second period is the longest stage of the game and should be played until the child is readily identifying the shapes without needing verbal or non-verbal cues from the adult.

***Only move to the third period when you know the child will answer correctly!***

If the second period has gone on for a while, and the child does not appear confident with the names, smile, and let your child know you will work with them again tomorrow. They mustn't feel as if they have failed in any way. Instead, they are having fun manipulating the shapes. If you are unable to move to the third period, try again on a different day.

#### 3rd Period: The “Test.”

During the third and last phase, we ask the child to recall the name of each shape. If the child does remember, the test should be short and sweet:

“What is this?” The child should respond, “a square!”

That’s it! On a different day, we will review the names of shapes the child already knows and introduce the names of new shapes.

Now you can try offering these types of lessons at home! Are you ready?