Challenge Friday: Designing Yeti Houses


When Lego released the series 11 minifigures, there was a yeti included as one of the 16 in the series. I knew the kids would love that one, so I collected 11 yetis (one for each pair of students) and had them participate in a Challenge Friday activity centered around the yeti. First we read about the yeti to find out what the creature is. We talked about mythical creatures and I showed the children where they could find books about the yeti and other mythical creatures if they wanted to learn more about them (which they very much did in the days to follow). Then I announced the challenge.

We talked about architects and what they do. I emphasized how architects make plans and think through what they’re going to build BEFORE the building actually happens. I explained to the kids that the yeti was hiring them as the architects and he had certain specifications that he wanted them to include. Beyond those criteria, however, they could be as creative as they wanted. They could also be creative in how they chose to include the specifications. This discussion was done in Spanish and the ideas that we we’re discussing we’re written on the board in Spanish. We’ve been talking a lot about cognates and the kids have gotten very good at identifying cognates. They immediately noticed that “arquitectos” and “plan” looked and sounded like the corresponding English words. I kept the chart paper with the specifications written in English up on the board as well so that students could refer to either language while they were making the yeti houses.

The kids set off right away, working on first a plan and then building the actual houses.

While they were building the houses, I wrote a question on the board that we would discuss during our Share Circle that would happen next.

After 20 minutes of building, the kids brought their completed houses over to the Share Circle. They thought about the answer to the question I had written on the board: “How do you know the yeti is happy with his home?” Then they shared with the partner sitting next to them. I called on several partners to share with the whole group. Some students said that they knew the yeti was happy because they “included all of the specifications” in the house, while others said it was because they had provided various forms of entertainment and comfort for the yeti, including flat screen TVs, laptops and video games, hot tubs, and heated chairs.

Finally, we went around and took a picture of each yeti house from directly above to get a bird’s-eye view. The kids went back to their tables and revised their floorplans to make sure they were accurate maps of the houses that they had created.

They really loved doing this challenge and requested to do it again the following week!


Cartober: Challenge 3: How many 50g blocks do you have, Ms. Tice????

Our final challenge for Cartober took the remaining Fridays in the month of October.  The first step was making a car that would have a place to carry up to ten 50 gram Lego blocks.  We raced the cars down our ramp in a hallway where the cars could roll as far as possible.  We used rulers to measure the distance each car rolled.


Kids worked in groups of 3 to build their cars.  Once we were ready to start racing them down the ramp and measuring the distance, the kids picked “jobs”.  One kid needed to be the Measurer, one needed to be the Recorder, and one needed to be the Racer.  They would switch jobs with each trial, so that each kid had a chance to measure, record, and race.

The first trial was just the car by itself with no 50 gram blocks.  Each group raced, measured, and recorded.  If a car broke on the way down, the group was allowed to go fix the car.  On the second trial, we added one 50g block.  On the third trial, we added five 50g blocks, and on the fourth trial we added ten 50g blocks.


The building of the car and doing the four trials were not done on the same day.  We split it up so that the kids built a car and raced it with no 50g blocks to get their initial measurement on the first day.  Then we placed the cars in gallon-size ziploc bags and I wrote each group’s names on the bag.  The next Friday, we finished the trials.


After all the trials, we reflected on the effect of the added weight to the cars’ distance.  We talked about what this could mean.  Many kids said they were surprised that the weight would make the cars go so much faster.  They had predicted that the weight would slow the cars down.  Several kids remembered a field trip they took to a local ski resort in second grade to go snowtubing.  They made the connection that it made sense that more weight would make something go faster because when you snowtube, you go farther if you connect more tubes together.

The kids loved Cartober and were sad to see the car racing come to an end.  Little do they realize, but this will not be their last car race…. MUAH HA HA HA HA!

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


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.

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.


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.


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!


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.


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.