Overview | The Math | The Lesson

The Lesson

The lesson consists of two parts:

1. Construction of the solids
2. Study the solids

Construction of the Solids

Distribute templates, scissors, tape or glue, and decoration supplies. Remind the participants to mark the creases very well before folding. Decorate before or after putting together. For a mobile or holiday decoration, attach a nylon loop or string to hang. Or leave a face untaped to build pretty little boxes. Voilà!

Study the Solids

Let the students physically explore the 5 models they constructed for this part of the lesson. Distribute the Platonic solids handout.

1. Have the children count F, the number of faces; E, the number of edges; and V, the number of vertices; and record their results on the handout's table. Next, they should compute
            F + V - E
   for each solid. Let them discover that number is always 2!!


2. Direct your students to analyze the information in their tables and identify and record the pairs of dual polyhedra.


3. Ask the question: for which of the 5 solids are you able to place your fingertip on a vertex and "redraw" all the edges without lifting your finger and without going over a edge twice? (Or, equivalently, which of the 5 solids can be constructed by just bending a long piece of wire?) Again, let them discover and record the answer. (Only the octahedron.)

Download the Lesson Kit (pdf)