Lesson Plan 5

Used in third grade class. Adaptable for all grade levels.

Eggs-traordinary Arches

Activity: This activity was one of the 'Building Bridges' activities used with my third graders to reinforce that there is a center of gravity in everything. It was stressed that the arch design in building is a great supporter of weight. There is an equal distribution of weight. This activity can incorporate an understanding of the principles of bridge building and boat building.

Demonstration: Using four egg shell halves, the children will make observations, predictions, and inferences about arch building designs.

Procedure: Using masking tape, tape around the cracked edges of four egg shell halves. Place one shell half in each corner of a square piece of paper. The children predict the number of books (of equal weight) that the shells will support before they crack and crunch. The predictions are graphed. We used a Tally Graph. The books are stacked one by one until the crunch is heard. Children then compare their predictions with the actual number of books supported.

Discussion: During your discussion, use various levels of questioning techniques. For example: Was your prediction too high, too low? By how much did you over or under estimate? Would the shells have supported weight if the shells had been halved length-wise? What can we infer from this demonstration? Why was this design a good supporter of weight?

Follow up: As a follow up activity, have the children construct arch bridges. We built ours with blue construction paper and two sentence strips (one for the roadway, one (cut into thirds) for the arches. Boats were then designed using the arch design. Have a collection of pictures available showing arch designs in bridges and boats.

Writing application: Brainstorm with your class about where they have observed arch designs in the world, ie., the golden arches of McDonald's, rainbows, bridges, etc...) and compile a class book showing the various things and places that have the arch design. Put those creative minds to work!

Julie Tindal at Midland Park Elementary School

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