Geometry Fun

One of my favorite units of study with my students is geometry.  It’s so much fun, and there is so much for students to learn.  It’s always challenging for students to learn the difference between pyramids and prisms.  One of the best ways to teach the difference between various 3D shapes, is by having students create them.  I like to use marshmallows and toothpicks.  If you do this, I recommend telling your students that you have a bunch of fresh marshmallows for them to eat when they’re all finished.  Otherwise, students will eat too many while creating their projects.

Model the base of the 3D shape first

To help students I begin by modeling how to create the base of either the pyramid or prism.  I remind them that it is the base of either solid that creates the name.  For example, a triangular prism has a triangular base.  So, we begin by creating the base of the shape with marshmallows and toothpicks.  Then we begin building up.

Free Exploration

Once students create their first prism they get the hang of it, and are ready to create more with less guidance.  I usually give my students time to explore on their own, after creating the first prism together.  They become quite creative, and have so much fun creating their own 3D shapes.

Pyramids

Once students seem to have exhausted making prisms, I introduce pyramids.  Pyramids are created the
same way, except the sides all converge into a point.  Students are able to create pyramids very easily after making their own prisms.  The next day I begin my 3-D Shapes:  Understanding and Identifying Solid Prisms and Pyramids lesson with my students to further reinforce the lesson, and assess them.

I have students leave the pyramids and prisms on their desks to harden over night, and the next day they are able to take them home.