The Geometric Solids

“Many psychologists have spoken of the stereognostic sense, that is, the capacity of recognising forms by the movement of the muscles of the hand as it follows the outlines of solid objects.” Maria Montessori in Dr. Montessori’s Own Handbook

The child sorts the geometric solids by feeling their straight and curved sides, he then matches them to their correspondent base shapes.

Aim

The child can recognize the geometric solids that are found in the every day environment.

Objectives

• Learn the names of the geometric solids
• Gain awareness of the geometric solids found in the child’s everyday environment

Age

3+

Materials

• A basket containing the geometric solids
• A box with the base shapes
• A small mat

Control of error

Visual (when the child is not wearing a blindfold to perform the exercise)

Language

The names of the geometric solids: sphere, prism, pyramid,cube, cone, cylinder, etc.

Presentation

Place the basket containing the geometric solids on the table. Lay out the small mat as a contained space for this activity. Pick up a solid and slowly feel it. Pass it to the child and allow her plenty of time to explore it, feeling its roundness, angles and straight sides.

Once the child has fully experienced each geometric solid, you may offer the child three solids that differ in shape and introduce their names.

“The most attractive way of teaching a child to recognise this forms is for him to touch them with closed eyes and to guess their names…After an exercise of this kind the child observes the forms when his eyes are open with a much more lively interest.” Maria Montessori in Dr. Montessori’s Own Handbook

Show the child how to sort the solids, choose one for each family, i.e.: one curved solid, one plane solid, and one solid both plain & curved.

Further challenges

You may show the child how to place the solids on their bases. The child will discover that various solids share the same base.

Ideas

Extend the child’s learning by offering everyday objects, such as tea boxes, coffee cans to match to the geometric solids.

The child matches the geometric solids to the objects found the child’s everyday environment.

Provide the child with opportunities to create personal objects through junk modelling which supports the child’s discovery of those shapes that fit together and those that don’t fit.

You may also set out activities to help the child further discover the way that solids move: i.e.: marble runs.

“The sphere rolls in every direction; the cylinder rolls in one direction only; the cone rolls round itself; the prism and the pyramid, however, stand still, but the prism falls over more easily than the pyramid.” (ibid.)