This lesson is designed in 2 parts. The first part will take several days to complete because students will be building towers from several different materials. The second part will entail testing the strength of the towers and drawing conclusions about the materials used. The second part will take 1 day to complete.
Materials: newspaper, popsicle sticks, pasta, masking tape, and glue for building the 3 types of towers. You can choose a different building material depending on what you have available, but you want 3 different materials so students can evaluate the strength of the materials they have used.
You will need dictionaries, or other books that are the same size and weight to use to measure the strength of the towers.
The idea will be for students to use the same tower design with each of the 3 material choices. You will want the towers to have a way to set dictionaries (or other available weights) on top so students will want to build some form of platform. The goal is for the towers to be stronger rather than taller.
As students build the same design with different materials, they will have a chance at the end to draw conclusions about which materials and designs were the strongest. While initially the idea will be to build a design that stands and can bear weight (ie the shape of the object will help it perform the job it needs - which I remind students of our previous lesson on how the shape of the tool helped it perform its job, and now they need to think of the shape of the tower) by building the same tower 3 times, students can then think about the type of material they used and why that type might have provided the most strength. This will happen over the course of the building and then the Part 2 of the lesson where they will test the towers and draw conclusions about shape and strength of materials based on what they have seen.
I explain to students that for the next several days we will be building towers out of different materials. We will be testing the strength of our towers by placing dictionaries on top of them when they are done. We will think about the properties of the materials (what they are made out of) may determine how well the materials do their job.
We read together, "I can build a tower and test to see how strong it is."
Today I begin by introducing the tower experiment to the students. I say, " Are all buildings made out of the same materials? Are they the same shape? Same size? Did you ever wonder how the builder decides which materials to use to build a building?" I give students a chance to respond to these questions.Explaining Why Builders Might Choose a Material
"Today we are going to begin an experiment that will take us several days to complete. You will be building towers out of 3 different kinds of materials. You will use the same basic design for your buildings, but you will try different materials. You will need to build a tower that is at least 1 foot tall. It will need to have a platform at the top the size of a piece of paper. After we have built 3 towers, we will place dictionaries on top and see how many dictionaries your design will hold. The idea is not to do better than your classmates, but to figure out which of your 3 towers are the strongest. The scientific question we will study is, "Which materials, paper, pasta or popsicle sticks are better for building a 1 foot tall tower?" We are interested in which tower will stand up the longest of your 3 towers. Your friends may have a tower that holds 5 dictionaries and yours holds 3, but what we are going to compare is which one of your towers held up the longest and is that the same for all of us?"
I pause here for students to ask their questions and to try to respond to what they are understanding so far. I want to answer their questions and concerns before getting them started on the building.
I show students the pile of newspaper and masking tape. I say, "today you will build with only these 2 materials. You need to think about how to make your tower stand and that it will need to have a way to hold these dictionaries. I am going to show you one way you might want to use your paper. Start with 1 full sheet of newspaper. Start at one corner and roll the paper up tightly in a roll. Tape the roll at both ends to hold it. Now you have a piece that you can use for your tower. The rolled paper tubes can be the pieces that you put together to make your tower."
"When you get with your partner, share your ideas for building your tower. You might even want to sketch what you are planning to do. Once you have an idea, come and get the newspaper and tape. You may use scissors as well as the newspaper and tape."
I have students get out their buddy wheels and one student draws a number. Students partner up and begin work on their towers.
Students need some background for how to make things strong before they can design their towers. I start by showing them some of the furniture in the room and ask, "what is holding up the chair?" "What makes the shape of the easel strong enough for me to lean on?" "How is the table standing?"
I let students answer each one. I am hoping that they will use some of these ideas as they design their towers but as I circulate around the room I am ready to ring the bell and provide a mini lesson if needed.
My mini lesson involves a demonstration. I say, "I see many of you have drawn a straight side to your tower. I wonder what is holding up that side? Do you think this paper will stand by itself, even if I make it into a cube as many of you have drawn?" I let students respond as I demonstrate making the paper into a cube. The cube stands, but barely. I say, "Now if I put this dictionary on top will it hold it?" Children laugh when the dictionary crushes the paper. "What might I do to make it stronger? Think of the table, or the chair or the easel, what do they use to make them stronger?" I point to the poles/legs holding each one. "Could I make something like that? I noticed someone suggested rolling paper, what would happen if I rolled up a few pieces of paper and put them on the corners of my tower, would that help? Again I demonstrate as they predict what will happen.
I end my mini lesson by saying, "I could even put my rolled pieces sideways, or crosswise like the chair legs to make it stronger."
I hope this will help students to rethink their designs and to add supports as needed.
I give students time to work on their towers. I circulate around the room to ask questions and hear what students are thinking as they are building. Building the Newspaper Tower From Their Design I also provide assistance rolling the newspapers into tight tubes.
After the groups have started rolling newspaper and have talked about what they will do, I stop the group for a few minutes and give them some suggestions. I tell students that we will not be testing their towers for strength today, but they may want to place a single dictionary on their tower just to make sure it fits.
In order to help students with this project, I provide several supports. First I encourage students who are struggling to walk around and look at what other groups are doing. Students can learn from the ideas of others.
Second, I place out pictures of bridges, the Eiffel Tower, children's engineering design books and photographs of other metal structures. I encourage them to look at the pictures to get ideas for how they might join their pieces together. We have not talked about how different designs may have more strength because we are thinking more about the materials in this lesson, but ideas for how to engineer their tower may help them to build a stronger design.
Finally, I suggest that they look at how things like the chairs and desks in our room are built, especially the legs. They may get ideas about cross supports by looking at the familiar objects in a new way.
I am hoping that by providing several visual supports, students will try some new ideas as they create their towers. I could spend another lesson talking about structural design, but instead I have chosen to provide a variety of visuals that students can use independently. Students often learn from trial and error, and from looking at what others have done. I would rather have students try their own designs, than for me to tell them exactly how to build the tower.
For the next two days, students build two additional towers. We first talk about the towers that they already built. I ask students to think about their designs and why they chose the design that they did. I also want them to look at what other students have done so we walk around the existing tower display to notice how the towers were built.
After we have seen the towers I ask, "are there things that you notice about the towers that you want to share?" I let students share their observations.
"Today, we will build a second tower. Building The Second Tower Today you will use popsicle sticks, tape and glue. Again you may use scissors as needed. You should try to make a tower that is the same basic design as your first tower. You may change it a little because of the new material or because of something you noticed in your observations today that you want to try. Again, remember that you will need to be able to place a dictionary on top of your tower. Your tower should stand at least 6 inches high from the floor to where you place the dictionaries. You will work with the same partner as yesterday." I ask for questions and then let students get to work. I circulate around to observe, listen and ask questions.
I repeat this process on the third day using pasta, glue, tape and elastics (to band groups of pasta into the supports) as the materials. I remind students that this material may be a little harder to work with, but that they should again try to make a tower similar to the first two.
After 3 days of building and displaying, we have a large variety of towers built. I tell students that in our next lesson, we will test the strength of the three towers they built. I would like them to close today by writing the 3 towers in the order they think will be strongest, next strongest and weakest.
I ask them to take out their journals and write the words newspaper, pasta and popsicle sticks in the order they think will be strongest first, then next strongest and then weakest. I tell them that they do not have to choose the same order as their partner. This is their prediction and we will check it after our next lesson.
Predicting is an important part of the scientific process and one that is not always easy for young children to do because they want to be correct. By making the prediction today, and then recording our findings on a separate sheet, students will be able to see if their prediction was correct, without wanting to change it before sharing.