This lesson can be adjusted if students need additional time to construct their models. It can also be divided into two or three shorter sessions if needed.
**Before the lesson, you may want to hard boil the test eggs used in the student investigation. They will allow young students to examine the egg after the test, and they can be peeled, rinsed, and eaten after the experiment so they don’t go to waste!
Engage: Pose introductory questions and create interest.
- If you completed the other “Solutions from Nature” lessons, remind students that their previous design problems looked to nature for ways to insulate from the cold temperatures and provide stability to buildings.
- Tell the students that today’s design problem is about protection, and they will also be looking for more ideas from nature.
- Break one raw egg into a plastic container. Place the shells in the second container. Ask students to describe the inside and outside parts of the egg by looking at them and touching them.
- Show students a second raw egg and ask, “What would happen if I dropped this egg off the edge of the table?” Put the egg in a zipper sandwich bag and demonstrate.
- Show students the hardboiled egg; crack, peel, cut in half, and place in a third plastic container. Let students examine and describe the hardboiled egg.
- Show students a second hardboiled egg, and let them predict what will happen if you drop it off the table. Demonstrate and discuss what happened. What is the purpose of the egg shell? What happens if there is too much force on the shell? Is there a way to protect the egg shell and keep it from breaking? Can you think of a way that we try to protect our bodies from breaking or getting injured? [shoes, seatbelts, armor, shields, helmets, goggles, kneepads, shin guards, football pads, etc.] List these on the chart paper or board.
Explore: Have students look for connections to nature.
- Remind students that we can get ideas from nature to solve our problems. Show students a photograph or digital image of a turtle. Ask how the turtle protects itself from predators. Ask if students can name other animals that have protective coverings (crab, snail, pill bug, armadillo, porcupines, etc.).
- Display or pass out photographs, book illustrations, or digital images of these animals, and have students note similarities and differences. Turn and talk with a partner, then share with the group. What connections can students make between these animals and the protective gear they listed earlier in the lesson?
Explain: Why is this important? Define the problem. What design elements need to be considered?
- Show the YouTube video of the boy testing out helmets.
- After viewing, point out that this boy was testing the effectiveness of actual helmets, on large melons, from a second story balcony. This experiment will be a little different—they will test on a smaller object (the egg), from a lower distance (the tabletop), and students will have to design the protective gear themselves.
- Tell the students that today they are going to be engineers—scientists who solve problems. Today’s problem is: How can we build a protective helmet that will keep the egg from breaking when it falls off the table? Write this on the chart paper or the board.
- Ask students to suggest ideas for keeping the egg from breaking when it falls. List important design elements on the chart paper or board. These might include slowing the egg down when it falls, (decrease speed), having something hard or soft around it (cushion or shock absorption), making sure the egg stays in the helmet (restraint), or whatever else they think of. Have students think about the protective gear they listed and the animal characteristics they observed. Have them think about the video they just watched—why did some helmets work better than others at protecting the melon? Other ideas from nature to suggest—what does a cat do when it lands from a high jump (bend its knees), leaves and dandelion fluff floating (think parachutes), hickory nuts are heavy with a hard shell to protect them when they fall from a tree, but maple seed pods are smaller, lighter, and have the helicopter shape to help them slow down and fall gently.
Elaborate: Allow students to work alone or in groups to design and create an egg helmet.
- Distribute the Student Record Sheets. Have them copy the Problem (“Build a helmet that protects the egg when it falls.”) off the board. Show students the various materials they have to work with, and let students talk about what materials they will choose, writing them in the Materials section of the Record Sheet. You can allow students to work alone or in pairs—divide them up, or ask if students have a preference. If you are allowing either option, just make sure you have enough eggs and materials on hand for the number of projects being created. [***You can break the lesson here, allowing for a separate session to construct the helmets.]
- As students begin making their plans, allow them to come and choose materials from the supply table and begin working. Let them use plastic eggs during the construction phase, to allow them some trial and error without breaking all the hardboiled eggs early! As they finish the helmets, remind them to complete the Design and Predict portions of the Student Record Sheet. [***You can break the lesson again here, testing the helmets in a final session. Some students may need less time and transition to a different activity, some may need more time, some may have glue that needs to dry overnight, etc.]
Evaluate: Test the student models, compare results, and discuss findings and applications.
- Make sure the plastic eggs have been replaced with a hardboiled egg and secured in the helmets. Let partners drop the egg helmets one or two at a time off the table. They may have to disassemble the models to inspect the eggs. Have them record what happened on the Results section of their record sheet.
- After all the helmets have been tested, let students think about the Reflect section. Why did something work well, or not work? What did you learn about protecting the egg from impact? Would you change something on your helmet and try it again? Allow students to share their reflections.
- Conclude by discussing the following questions: “Which materials provided the best protection? Did the design of the materials help protect the egg? How did your designs imitate the objects we examined from nature? How could we make better protective gear in real life?”