# Using the Geoboard

Henri Picciotto

The geoboard provides a nicely constrained environment for mathematical exploration, and lends itself to many activities where students can discover or apply important ideas in the K-12 curriculum. This page is a hopefully comprehensive list of links to geoboard activities on this site and on my blog.

All activities I link to below can be done on the CircleTrig Geoboard, a two-sided manipulative I designed. On one side, an 11 by 11 traditional geoboard. On the other side, a circle geoboard, with radius 10 cm, and a 360° protractor. It is available from Nasco.

(However, most can be done on traditional 11 by 11 geoboards, or traditional circle geoboards. An online geoboard is available on the Didax Web site. In my experience, "virtual manipulatives" do not work as well to generate student discussion, but they are useful if you don't have the physical version, and also to discuss solutions on the projector or to get images to use in worksheets or student reports.)

Compact introduction to the geoboard for teachers: one page | two pages

## 11 by 11 Geoboard

Area: Labs 8.4-8.6, 9.5
Distance: Labs 9.2, 9.4, 9.6
Similarity, Slope: Labs 10.1, 10.2

(Some of these lessons overlap and complement the ones in Geometry Labs)
Area: Lessons 1.12, 2.12, 4.12, 6.12, 11.A
Distance, Square Roots Lessons 6.12, 7.12, 9.1-9.4, 9.A, 9.9, 9.C,
Similarity, Slope: Lessons 3.12, 8.3, 11.3

Connect the Dots: lattice problems and puzzles for teachers (and students)

### Blog posts

Geoboards and Dot Paper
Geoboard Triangles
Inscribing Geoboard Squares in Polyominoes
No Three on a Line
Heilbronn's Triangle
Geoboard Problems for Teachers

### On this site

Proving Pick's Formula
Dot Papers
Connecting the Dots! (presentation slides): html | PDF | Keynote