Different Geometric three dimensional forms including; Sphere, Ovoid, Ellipsoid (Curvilinear solid), Cone, Cylinder (Combination solid) and the Cube, Triangular Prism, Square Prism, Triangular Pyramid, Square Pyramid (Rectilinear solid).
These should be displayed on an open tray on a shelf in types of solid. The Curvilinear Forms stay still with the use of three rings. An attractive piece of cloth large enough to cover all of the forms easily when they are on the tray
A set of wooden cards with two-dimensional shapes which correspond to the faces of the rectilinear solids.
Introduction: With the Solids only
- Bring the solids to the working mat
- Isolate three contrasting solids, e.g. the Sphere, Cube and Triangular Pyramid
- Look at all three carefully before selecting one with both hands
- Close the eyes and feel all of it’s characteristics
- Put the solid on the mat and invite the child to repeat
- Repeat this with the other two solids
- In the ‘Three Period Lesson’ introduce the names
- Introduce the other solids as above recapping the known names in the second period of the ‘Three Period Lesson’.
- Bring the tray with all the solids, the three stands and the material to the Working Mat
- Lay out all the Solids at random and cover with the cloth
- Put both hands under the cloth and feel one solid, name it
- Reveal the solid out as a control
- Continue involving the child as appropriate
- The child feels and names all of the solids
- The Directress requests the child to find a particular solid
- Bring the cards and show all of them to the child and try to match one solid at a time.
- ‘How many solids share one card?’
Bring the cards and show all of them to the child and ask her their names if she has received the appropriate ‘Three Period Lesson’. Remove all the solids from the tray and taking one at a time try to match each face to the two-dimensional shape on each card. If the child has difficulties help her. Note: For two dimensional shapes it is necessary to use the stands and look from above.
- ‘How many shapes can the solid fit into?
Put the cards in a pile and take the top one, try to fit the faces of each solid into the shape in every direction. When one card is complete put it to one side and try the next one
The names of the solids
- To refine the Stereognostic sense
- To bring awareness of three-dimensional shapes to objects in the environment
- To prepare for Geometry
Age at Presentation:
After three and a half years, preferably when the names of simple two dimensional shapes are known
Games (Further Exercises):
- Put the solids in sand to make a reverse model of their shape
- Put the solids in sand and perform it’s characteristic movement by turning it about it’s vertices, roll it, rotate it about a point or face, twist it about the centre
- Make a clay model and cut with wire to reveal symmetry or layers, partial pairs, other internal forms and smaller versions of the original shape
- Handicraft: create two-dimensional shapes in metal or cardboard and by attaching string spin the on an axis to ‘reveal’ a related three-dimensional shapes, e.g. an isosceles triangle forms a cone, a diamond a rhombus, a circle a sphere, a rectangle a cuboid
Older children no longer enticed purely by the desire to touch can be encouraged to work with these if they join the class later can be asked to polish them to connect them with the material.