Cartober: Challenge 2: The Gingerbread Man’s Great Escape

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Since we are calling October “Cartober”, all of our Challenge Friday challenges are related to cars and the simple machine wheel-and-axle. Each challenge during the month of October builds on the challenges from previous weeks. We are also in the middle of a Fairy Tale unit in our language arts classroom, so I wanted to find a way to combine Challenge Friday, Cartober, and fairy tales! The challenge this week: find out what makes cars go faster and build the fastest car possible!

We started by reading the classic story of The Gingerbread Man. We talked about the elements of a fairy tale that the story included, just as we had done for all the other fairy tales that we had read during the unit. The kids noticed something important about the ending of The Gingerbread Man – that it didn’t end with a “happily ever after” for the gingerbread man. They noted that this was unusual for a fairy tale because most of them have happy endings. This led us to the challenge.

I told the kids that we were going to rewrite the ending so that the gingerbread man does end up happy instead of eaten. We called it The Gingerbread Man’s Great Escape. I told them that they would have to make a car like last week for the gingerbread man to make his getaway, but they would have to make the car go as fast as possible, and they would have to think like a scientist to do it.
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First we brainstormed ideas for things that could possibly make a car go faster. The kids suggested things like more weight, less weight, bigger wheels, smaller wheels, using Lego pieces with holes so that air could pass through easier, and using wheels that spin easily.

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Next I told them that they should try any of those modifications to their car to find out if it really does make the car go faster. I asked them how they would know scientifically that the car was actually going faster. I asked, “Will you just watch and guess whether or not it’s actually faster? Is that what scientists do?” One student suggested that we record something. I asked what exactly we would be recording. Several students shouted out, “Speed!” I asked them how we would do that. “What device do we have that records speed?” They couldn’t think of anything. Another student suggested that we could time the cars as they go down the ramp. Again, I asked what device we would use for that. We ended up using the stopwatch feature on the iPod touches.

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The last conversation topic that we had before we started building and racing was about the idea of changing only one variable at a time. I asked them what would happen if they added weight, put on bigger tires, AND used a piece with holes, and the car went faster. How would they know which thing made the car go faster? They realized they wouldn’t be able to tell. So I reminded them to change only one thing at a time and then record the time before trying out another idea. I gave them each a little Lego gingerbread man figure to put on their car to help him escape from the fox!

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The kids set to work right away and tested out ideas, recording the times as they went. It was interesting that many of them still had misconceptions about what exactly they were recording. Some would come to me and show me the time on their stopwatch and say, “Look at the speed now!! It’s way faster!” They were equating time with speed. Others needed help understanding what “1.6” means as a number.

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Finally we met in a share circle to explain our results and conclusions to the rest of the class. Most kids came to the conclusion that adding more weight made their car go faster. A few came to other conclusions. We talked about the adding more weight and what effect it has on a car. This was an important idea because it has to do with their final challenge of the month. Then they recorded their conclusions on a reflection sheet that they glued into their notebooks.

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Cartober: Challenge 1: Make a Fast Car

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We are renaming the month of October “Cartober” because all of the challenges this month will be related to cars, speed, force, and gravity. The first challenge was very simple: build a fast car.

I went to Lowe’s expecting to buy materials to build a ramp with three or four lanes for the cars to race down. I went down the aisles, pricing the plywood and other materials I was going to need to build this ramp. I also became aware of the amount of time I was going to need to build it. I vaguely played with the idea of having the kids build it instead of just me. As I passed the aisle with siding for houses, I noticed a particular piece of siding that was super long and was molded in the shape of three lanes on the underside. How perfect! $12 and I had the perfect bendable three-lane ramp with no other prep work necessary! I was super proud of myself!
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On Friday, I explained the rather simple challenge to the kids. They simply had to build a car that would travel down the ramp successfully. This particular challenge was not meant to be difficult because the challenges coming up for the rest of this month are meant to build on the basic idea of making a car. We talked about another simple machine, the wheel-and-axle, and I drew another diagram to label the parts. We also reviewed the previous two simple machines that we had used in earlier challenges – the lever and the pulley.

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Due to the simplicity of this challenge, I decided to put my third graders in more of a leadership role by partnering with a second- and first-grade class. We invited two classes to join us and each second or first grade student had a third grade student as a buddy. The kids were very excited to get to work with younger students and some got to be partners with brothers, sisters, or friends. Before the younger kids arrived, we talked about how to be a good leader – how to play the role of a guide or model while including the ideas of someone who has less experience than you. The kids suggested great ideas. One kid said, “If you know something isn’t going to work, you could ask the younger kid if they want to try it a different way, but if they say no, you should just let them have the experience so they can find out for themselves.” Another kid said, “You could include some of your ideas and some of theirs.” Still another suggested, “You could assign jobs like one of you make the base and wheels and one of you make the top design.”

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When the younger students came, I explained the task and read a story to everyone out loud. It was a picture book called Roy Makes a Car. All the children loved the book! They thought it was funny and it was a perfect interest level for first to third graders.

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The kids partnered up and began making their cars. They had 20 minutes to build, test, and modify their cars. We discussed new vocabulary like modifications. Finally after 20 minutes, I rang the chime to announce that the races would begin. We allowed the first and second grade partners to race the cars first so that they could head back to class after racing. Three kids could race at a time. The third grade partners collected their cars at the bottom and waited patiently for their turn to race.

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After everyone had a chance to race their cars, we met in a circle for reflection time. I asked the kids what part of their car they liked the best and what they would change if they had more time. It was interesting to hear some of the ideas of things they would change. Several kids said that they would remove blocks to make it lighter because, “heavy cars go slower.” This was a common misconclusion and it leads perfectly into next week’s challenge. We will be using the scientific method to determine what actually makes a car go slower or faster. The final part of this week’s challenge was using an app called Tellagami on the iPod touches. The kids took a picture of their car and made a short video describing the things they liked about their car and/or what they would do differently next time.

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Everyone had a great time and they seemed to really enjoy working with kids from different grades. When I checked in with the second and first grade teachers later in the day, they reported that their kids had come back from the experience saying it was the best day ever!!

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