A Math Forum Web Unit
Tom Scavo's

Introduction: Materials

Contents || Math Lessons

[Materials] [Length] [Area] [Pick's Theorem] [Dot Paper] [Epilogue]

[Lines] [Squares] [Rectangles] [Parallelograms] [Right Triangles] [Bibliography]

### Materials

Geoboards come in all shapes and sizes. These lessons, in particular, assume a square 5 x 5 geoboard with a total of 25 pegs:

Figure 1. A 5 x 5 geoboard.

but other configurations are also possible. It is advisable, but not essential, that the geoboards be constructed in such a way that four of them fit together to make a square 10 x 10 board with 100 pegs:

Figure 2. Four 5 x 5 geoboards fit together
to make a 10 x 10 geoboard.

This desirable feature permits extended activities and gives the students additional opportunities to discover geometric and algebraic patterns. The ideal geoboard will also have a circular configuration on its reverse side.

Unfortunately, few commercial geoboards have these specifications. On the other hand, students can build their own. All that's needed is a square piece of hardwood (with beveled edges) and 25 brass pegs (the kind that don't pull out). It's fun and educational to design and build an aesthetically pleasing and functional geoboard. If you find that such a project is not feasible, however, have your students construct paper models instead. Either way, determining the proper spacing of the pegs (so that four geoboards fit together to make a larger geoboard) can be a rewarding and challenging exercise.

A large number of rubber bands - all sizes and colors - will be needed for these activities. Each student must have a generous supply of rubber bands. Be aware of potential problems, however. Most teachers will want to make it very clear at the beginning of the unit that rubber bands are to be used for geoboard activities only. All other uses are inappropriate and not allowed. A written contract to this effect sometimes helps students to take this important rule seriously.

Finally, it's a good idea for students to record their geoboard activities on paper. Dot paper serves this purpose well and should be freely available. Each student will also need a pencil, eraser, and ruler.

[Materials] [Length] [Area] [Pick's Theorem] [Dot Paper] [Epilogue]

[Lines] [Squares] [Rectangles] [Parallelograms] [Right Triangles] [Bibliography]