Getting Carried Away With Polyhedrons
- Grades: 6–8
In geometry, it’s the three-dimensional shapes that always stump my students, and
I am always looking for new approaches to teaching polyhedrons. Luckily, there are some excellent resources out there. Read on for instructions for making tetrahedral kites and teaching polyhedrons by folding circles, and for a great illustrated dictionary, perfect for visual learners.
When teaching surface area and volume, tetrahedral kites are great at holding students’ attention. They provide a high-interest reason for doing some basic surface area calculations. Materials needed include:
- Tissue paper
- Nonbendable straws
- Kite string
If you've never done this activity, a number of sites provide step-by-step instructions for you and your students. I like the instructions on NCTM's Illuminations and on two class Web sites, by teachers Jill Britton and Mrs. Glenda Woodburn . Before doing the activity, you might also explore Alexander Graham Bell’s work with tetrahedral kites. You'll find information at Century of Flight and at Best Breezes, a site on kites, and in the article "Alexander Graham Bell's Flights of Fancy." It takes my 6th graders two to three class periods to complete the kites, including some time for discussion.
Another great resource is Wholemovement, which uses circles to teach polyhedral forms in a hands-on way. I generally begin my unit on three-dimensional objects by having students fold and study circles, as Wholemovement recommends. It has proven a very effective way to translate fairly sophisticated geometric ideas to 5th and 6th grade levels of understanding.
Scholastic publishes a great book, The Usborne Illustrated Dictionary of Math, that explains abstract geometrical concepts and ideas plainly enough that even young students can wrap their heads around them. Having this book in the classroom gives my visual learners a way “to see” 3-D geometry in a 2-D format.
I hope you enjoy these resources for teaching polyhedral figures. Please share additional ideas and links that have worked for you. I can’t wait to hear your thoughts.