This lesson can be divided into 3-5 smaller chunks, depending on your schedule or the attention spans of your children; suggested stopping points are listed below.
**Before the lesson, ensure that the YouTube video links are working properly. Also, you might take a walk around the school grounds and see if you can find trees that are large, or have many visible roots around the base—part of the lesson is to examine these with the students.
Engage: Read a story, then pose introductory questions and create interest by examining a plant.
- Read the story “The Three Little Pigs” to the children. As you read, have students discuss the problem in the story (needing a sturdy shelter to protect the pigs from the hungry wolf). What kind of houses did the different pigs build? What materials did they use? Which ones worked the best? Finally, discuss that this is a made-up fairy tale. In real life, a pig wouldn’t build a house like that, and a wolf wouldn’t try to blow it down. But ask, do the students know of real life things that might cause a building to fall down? (wind, storms, tornadoes, etc.)
- Tell the students that today’s design problem is about Stability, and we will also be looking for more ideas from nature.
- If you completed the “Solutions from Nature-Insulation” lesson, remind students that their previous design problem was about ways to insulate from the cold temperatures. Remind them of the gloves they constructed. Remind them of how they looked for ideas from animals who have insulation in or on their bodies. Today we will look at plants in nature that are sturdy or stable—they do not fall over easily.
- Begin by showing students the small potted plant—remove the plastic covering and expose the root system. Review the parts of a plant (leaves, flower, stem, roots). Remind students that stems and roots help deliver water and nutrients, but they also provide stability to the plants.
- Introduce the word “Stability,” which means an object or system of objects that stays balanced and in place without falling over. Plants are living things, but they don’t have muscles and body parts that let them move around like animals and people do. So they have body parts that help them stay stable and in place. We can examine these features to help us create stable things. Just like the little pigs in the story needed a stable house that wouldn’t fall over when the wolf huffed and puffed, humans need stable shelters, and we can look at plants for ideas on how to build them.
[***This might be a good place to stop the lesson and continue later, as the next part of the lesson will be a nature walk outside.***]
Explore: Have students examine trees to discuss their stability, and experiment with a paper cup to propose variables that might make the cup more stable.
- Tell the students that today they are going to be engineers—scientists who solve problems. Today’s problem is: How can we build a house that is stable? Write this on the chart paper or the board.
- Ask students to think about how builders can get ideas from trees about stability. Take a nature walk around the school grounds and examine the different trees. Is there a breeze blowing? Which parts of the trees move more? Which parts move less? Examine the trunk and feel how sturdy it is. Examine the ground—do you see evidence of the root system? How thick are the roots? How far can you see them stretch out along the ground?
- Return to the class and discuss what you saw—explain to the students that the root system of a tree is very large. Remind them of all the roots they saw on the small plant—think about how many roots it took for a small plant. How many roots would go down into the ground for a very large tree?
- Show the first YouTube video link, of the relocation of a 100 year old oak tree. Point out the size of the root ball they dug up with the tree, and how many machines it took to haul the tree to its new spot. That is a lot of power to move a very stable tree!!
[***This might be another good place to stop the lesson and continue later, as the next parts of the lesson transition to the construction phase.***]
5. Tell students that they are going to test some ideas about stability on a cup, to give them ideas for the “houses” they will build later in the lesson. Distribute the cups and have students place them on their desks, pretending they are buildings. Have them blow gently on the side of the cup, and it will probably fall over or move around. Ask the students, “How can you make this cup more stable, so it won’t fall or move around?” Let them suggest and try ideas (perhaps manipulating the cup top or bottom side up, placing weight on or in it, etc.). Record these ideas on the chart paper.
Explain: Review vocabulary, make connections from the tree roots to the cup experiment to the real construction process of a house, plan small group investigation.
- When a student or students begin to discuss solutions about a foundation, anchoring it to the desk, etc., bring out the tub of soil. See if this sparks any new ideas. One idea to try would be to nestle part of the cup down in the soil, and then blow on it. This should be more stable.
- When students begin to try this, ask them to think back to the root system of a tree—part of it is buried in the ground. Tell the students that most houses start with a foundation—part of the house that is secured underground to keep it from falling over.
- Have students return the cups, and then view the second YouTube video, with the time-lapse photos of building a house. As you view the photos, look closely at the beginning, where they lay the foundation. How do they work up from there? What materials are they using? What shapes are being constructed? What might make a building less likely to fall or collapse?
- Write the words “Stability, Shape, Size, Weight, and Foundation” on the chart or board. Explain that these words are very important to builders and architects. They will need to think about them as they plan their designs with their partner, and look for ways to imitate the stability of the trees in nature.
[***This might be another good stopping point, before students will begin the construction process.***]
Elaborate: Allow students to work in groups to create houses that are stable, include some kind of foundation element, and can stand up to wind blowing on them.
- Tell students, “Today you are going to build a house with a partner. Make sure you think about a foundation for your house. When your houses are finished, we will place them in the soil tub, and test to see if they are stable when wind blows on them.”
- Divide students into groups of 2 and distribute the Student Record Sheets. Have them copy the Problem off the board from the beginning of the lesson. 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.
- As students begin making their plans, allow them to come and choose materials from the supply table and begin working. As they finish building, remind them to complete the Design and Predict portions of the Student Record Sheet.
[***This might be another good place to stop the lesson and continue later, as students finish their buildings. 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.
- Let partners bring their houses to the soil tub and place them firmly in the soil, anchoring the foundation. Have them blow on the houses and see if they move. You can also use a small fan and/or hair dryer to increase the force of the wind. Have them record what happened on the Results section of their record sheet.
- After all the houses have been tested, let students think about the Reflect section. Why did something work well, or not work? What did you learn about building a stable house? Would you change something on your house and try it again? Allow students to share their reflections.
- Conclude by discussing the following questions: “Were there any changes when we increased the force of the wind? Which materials provided the best stability? Which shapes had good stability? Did your foundations imitate the objects we examined from nature? How could builders and architects make more stable buildings?”