# Difference between revisions of "Geometric Solids"

Geometric Solids
Sensorial - Visual Discrimination of Form
LevelPrimary
Age3.5 - 6
Prerequisitesdiscrimination of form
Pink Tower
Knobbed Cylinders
MaterialsTen geometric solids:
sphere
cube
cone
cylinder
ovoid
ellipsoid
rectangular prism
triangular prism
square based pyramid
triangular based pyramid

Use of this material makes the child familiar with 3 dimensional geometric shapes and teaches their names. This activity prepares the child for geometry.

## Presentations

### Introduction to the solids

1. Select three solids and carry them to a mat or table (these can be carried in a small basket).
2. Name the first solid shape. Allow the child plenty of time to look at and feel the solid.
3. Present the other two objects in the same way.
4. Do a Three Period Lesson.

## Language

• A triangular based pyramid can also be called a tetrahedron.
• An ovoid is smaller at on end (like an egg), an ellipsoid has ends that are the same.

## Material

The triangular based pyramid can also be called a tetrahedron. The difference between the ovoid and the ellipsoid is that the ovoid is smaller at one end like an egg.

### Make Your Own

This material would be difficult to make on your own without some pretty good woodworking skills. There are, however, similar, far less expensive sets of geometric solids for sale online that were designed to be used in math classrooms. These are a bit smaller than the Montessori version. Neither set has an ovoid, but as the author of one blog pointed out, an ovoid might be easy to find in a craft store after Easter.

### Where to Buy

Geometric Solids Sets
Affordable Montessori \$49.00
Albanesi \$206.00
Alison's \$25.00 (unpainted wood)
Bruins \$150.00
E & O \$140.00
E & O \$140.00
ETC Montessori \$150.00
Hello Wood \$179.00 (stained blue)
Hello Wood \$174.00 (painted blue)
Hello Wood \$169.00 (unpainted wood)
IFIT \$45.00
Jump Start \$49.95
Materials Company of Boston \$135.00 (no triangular based pyramid)
Materials Company of Boston \$138.00 (unpainted wood)(no triangular based pyramid)
Montessori Concepts \$49.00
Montessori Educativos \$80.77 (unpainted wood)

Geometric Solids with Bases
A Plus Montessori \$49.95
Absorbent Montessori \$66.00
Affordable Montessori \$79.00
Alison's \$60.00
Alison's \$99.00 (unpainted wood)
Bay Area Montessori \$60.00
Bay Area Montessori \$60.00 (unpainted wood)
Cabdev \$179.00
E & O \$110.00
Juliana \$119.00
Montessori Educativos \$129.23

Plane Figures
A Plus Montessori \$9.45
Affordable Montessori \$12.00
Alison's \$18.00
Alison's \$10.00 (no stands)
Bay Area Montessori \$10.00
Bruins \$27.00
Cabdev \$33.00
E & O \$22.00
ETC Montessori \$27.00
Hello Wood \$32.00(stained blue)
Hello Wood \$31.00(painted blue)
Hello Wood \$30.00(unpainted wood)
IFIT \$9.00
Jump Start \$6.95
Materials Company of Boston \$26.00

Three Stands for Round Shapes
Hello Wood \$18.00 (painted blue)

Three-Part Cards
Affordable Montessori \$29.00
Alison's \$12.00
Alison's \$19.00 (no triangular prism)
Alison's \$9.99 (not laminated)(no triangular prism)

Definition Cards
Alison's \$22.00 (not cut out)(no triangular prism)
Alison's \$15.00 (not laminated)(not cut out)(no triangular prism)