## Nets of Crystals

Contents || Polyhedra in the Classroom || Suzanne's Math Lessons

[Crystallography]   [Crystal Systems]   [Paper Nets]
Students work in groups of 4.

Materials:
1. 4 sheets of the net of a cubic (isometric) crystal
2. 4 sheets of the net of a tetragonal crystal
3. 4 sheets of the net of a hexagonal crystal
4. 4 sheets of the net of an orthorhombic crystal
5. 4 sheets of the net of an rhombohedral crystal
6. 4 sheets of the net of a monoclinic crystal
7. 4 sheets of the net of a triclinic crystal
8. 4 pair scissors
9. Scotch tape
10. 1 bucket or basket to hold the materials during the project time

Procedure:
1. The materials are distributed and each group member prints their name on the face of each of the different polyhedra nets. [Later, when they are all mixed in the bucket, they will still be identifiable.]

2. Each group member is to cut out the polyhedra from the nets, fold, and tape.

3. As the students are working encourage them to use the vocabulary by asking prompting questions:

Which polyhedron has the crystalline structure of a diamond?

How many faces does it have?
[The faces are easier to count if you use the two-dimensional net rather than the three-dimensional solid.]
Evaluation:
1. As each of the polyhedra is finished, the group "checker" takes the product to Quality Control [the teacher who is checking to see whether the taping was done correctly so that all faces are showing], and if it passes inspection the polyhedron is placed in the group's bucket. If not, the checker takes it back to the group member for correction.

2. Group members are encouraged to help each other so that they will have six polyhedra models for each member in their group bucket.

These models will be used both as props for 'speeches' and to check work.