Lesson 1: Student Challenge

Teacher's Role

The teacher’s role is to present the challenge in an engaging way, encourage students along the way, and facilitate learning at the end. It is important that student teams struggle through the design challenge without design assistance. 

• Because the challenge is designed to drive the mathematics of the lessons to follow, it is important that students not know how to solve the challenge before giving it. The challenge must give the context and reason to explore the mathematics to follow: it is not practice but a way to necessitate the math which is to follow.
• In order to give a meaningful experience of productive struggle to students, teacher moves are included and excluded intentionally to increase students’ self- and peer-reliance. 

Hand out the lab sheet:

• I’m going to give you each a lab sheet. When scientists do experiments, they carefully keep track of everything they do and all of the information they get. The lab sheet is where we will keep track of what we do and our results.

Give very clear instructions to enable students’ independent work. 

• Before today, how many of you had ever built anything with spaghetti?
• Your challenge will be: In 18 minutes, build the tallest tower you can that will support a marshmallow at the top using only the given materials. 
• Each team gets 20 whole pieces of raw spaghetti, 1 yard of string, plus 1 yard of masking tape and 1 large marshmallow .  You’ll also get 2 tools that can’t be part of your tower: scissors and a measuring tape.  
• Tower height is measured from bottom of table to top of marshmallow.
• Use as much or little of your materials as you wish. You may not use any other materials.
• You may break or cut the materials, except the marshmallow (which must be whole at the top of your tower).
• Your hands must be off the structure when the 18 minutes ends. If your tower won’t stand at that point, that’s OK: Lay it down gently and don’t touch it again.

Remember that time is short. The purpose is not to build a perfect tower. We want to learn something about building with these materials. Try different things, and pay attention to what makes it strong. And also--learning from what each other is OK.

Ensure that everyone understands the instructions, and each team has its tape and marshmallow.   Send a member to get the team’s materials, lay on table.

Now take two minutes to think and sketch your ideas about how you might build your tower.

Next talk for three minutes with your team about what your plans are -- still hands off!

Have a visible countdown timer in the room.  Countdown to start the timer: 10-9-... 

During build:

• If a team has a single-level teepee with the marshmallow on top: “OK, that works -- let me take a picture of that, then see if you can make it taller.”
• Can you make it taller/stronger?
• Go look around at what other teams are trying and see if they give you ideas about how to make yours stronger.

Call out remaining time at 9, 5, and 1 minutes remaining, then count down final 10 seconds. When the timer hits zero, call out,

• Hands Up!
• If your tower won’t stand, that’s fine. Just lay it down gently. Nobody touching the towers. We still need them for the next activity.

Anticipated Problems

Some (perhaps many) teams will not manage to have standing structures. That’s OK! Since as the focus of the debrief and reflection is the features that worked (e.g., shapes: triangles vs. squares, diagonal braces, obtuse vs. acute angles; testing early/often with marshmallow; location of tape, etc.) & what students would try differently next time, the fact that some didn’t manage a standing structure is not a problem. Do not intervene in order to “help” a team accomplish a standing structure!

Possible questions to help:

• What’s not working well for you?
• Can you find a team that has found a way to solve that problem?
• That’s an interesting shape! Do you think that helps make your tower stronger?

Data Recording, Field Research

After building, it is important for teams to examine and learn from their own tower building and other teams’ towers. The teacher should attempt to keep teams’ discussions focused on what they can learn from other towers (and from their own experience).

Have each team measure their tower’s height in centimeters with their tape measure, and record them on their lab sheet.

• Come get a tape measure, and then record your measurement in centimeters on your lab sheet. 
• Next we’re going to look for the shapes that you made when you built your towers. For example, I saw this shape (draw non-rectangle quadrilateral) in <XXX’s> tower, and this shape (draw non-right triangle) in <XXX’s>.
• I want each of you to use your sticky notes to draw at least 6 shapes you can find in your tower. If you get stuck, talk with your team to get ideas. Put your sticky notes on the back of your lab sheet.

It is important to note that different shapes of triangles should be considered “different” for this activity -- but encourage teams to not use only triangles

Field Research: Have teams walk around as a team, examining other teams’ towers. 

• Now walk around the classroom as with your team. Examine other towers, looking for ideas about what you might do differently next time. 
• As you walk, what shapes do you notice? If you see some that are different than you put on your sticky notes, draw the new ones on the extra sticky notes.

The focus for the follow-up math lesson is shapes; feel free to bring up this issue

Clean up: I need to take pictures of all your towers. After I’ve taken pictures of your tower, you can clean up your space and put all the pieces in the trash.

Class Reflection/Debrief

• What worked well in this challenge?
  • (look for answers about building and about working together)
• Talk with your team about some ideas you have about what you would try differently next time. (1 min)
• Let’s hear some of those ideas about what you would try differently next time?
• When some of you had standing towers, I took pictures and then told you to make them taller or stronger. Why?
  • Look for ideas about wanting them to try to push their limits and try things they weren’t sure would work. Share this yourself if students don’t come up with it.

Please email scans or pictures of representative lab sheets to Brent: bjackson@srcs.k12.ca.us

• Report out: Teams share their process with the class. Have them think about:
  • What design struggles did you encounter?
  • How did you tackle them?
  • What was the outcome of your tower?
  • What shapes did you see a lot of? Were there any that you saw only once or twice?
  • What did you notice on your field research to see the other towers?

Teacher Role

How directed/constrained?

Once directions are given, let students build uninterrupted for 18 minutes. 

Teacher’s role during the Tower building  phase 

 Documenting (See formative assessment section below)

What kind of help/guidance/facilitation can I offer? 

As students build their towers, some teams may tape their towers to the table. This is fine to allow, but including it in the rules ahead of time, is too leading. If students ask if this is allowed, tell them yes.

Resist intervening as much as possible.  Any assistance, including “why didn’t you…?” or “have you thought about…?” can take away from the students important opportunities to develop SMP1 and SMP5. Only intervene in the following circumstances: 

• 1 student is doing all the work in a team for an extended period of time, excluding others from participating,  
• the team is clearly stuck to the point not doing anything, 
• the team is disturbing other teams.  

In such circumstances, ask questions that will still enable the students to do the design thinking. 

• What is causing that problem?
  • Not: Have you tried…?
• Have you all contributed any ideas you have about this problem?  Have you all worked with the materials?  
  • Not: Chantelle has some good ideas you could listen to.
• Have you looked around the classroom for ideas (aka scouting)?
• Can you think of ideas from similar things you know about, and how they work?

Timeline:

 (50 minutes total) 

• 5 minutes instructions (teams already formed in pre-lesson free play time) 
• 18 minutes building (not 15 minutes or 20 minutes, but exactly 18 minutes). 
• 10 minutes measuring and recording heights, gallery walk and team discussion of potential revisions
•  7 minutes completing lab sheet 
• 10 minutes debrief discussion