Part 1: The Raft
We often integrate literature selections into our design challenges and this particular challenge uses one of my favorite books, The Raft, by Jim LaMarche. The book tells the story of a little boy who is less that pleased to be spending the summer with his grandmother -a river-rat - in her cabin in the Wisconsin woods. With NO electronics, the boy is sure he will be bored beyond measure and his summer will be wasted. As it turns out, his summer is filled with adventure, exploration and independence, as well as a new found love for nature and his river-rat grandmother.
We often spend time in the imagine stage building background knowledge around the design topic. We learned early on in our STEM journey that the youngest children often lack the experiences and imagery that would allow them to be successful. Nearpod is one of my favorite interactive apps to use for this purpose. For this particular challenge, I created a Nearpod presentation that showed a variety of pictures of different kinds of rafts. Students were asked to make observations about the materials that were used, how the materials were used (platform, floatation) and how the materials were held together. Students were asked to list materials that they thought would make good model rafts and these were then shared with the group in real time. Students also drew a diagram of a model raft that they might build. This step forced them to apply some of what they had just learned about rafts and begin imagining how their raft might look. Their ideas were shared with me and I was able to push out their designs to the class, in real time, sharing the thinking. The last slide was actually a survey asking if students thought traveling the ocean by raft would be exciting, challenging or scary. This information was put into a graph and pushed out for the class to see.
Investigating possible materials is also an important part of the Imagine stage in the engineering design process. We investigated materials that could be used for the platform, some that might make good floatation devices and finally adhesives...what would work to hold the raft together. The data gathered during this time would be critical in making material selection decisions in the planning stage. You will notice that the craft stick was the only platform choice that was both waterproof and not flexible. Most students chose this for their platform which told me that they were attending to the data gathered during the investigation. Floatation materials were tested for waterproofness and whether or not they would take on water (which would lead to sinking). Finally, adhesives were tested for waterproofness, whether or not they would hold things together and how they might be used in designing a model raft.
Students drew a labeled diagram of their model raft and listed materials and amounts they needed. This stage is particularly important because it forces students to commit to a design,apply what they learned about the properties of the different materials to consider amounts of materials (leading to less waste).
The building stage is a BUSY time! I did not get any photos of the kids building...but I did cut a lot of duct tape!!
Testing and Improving
Each student had an opportunity to put their raft into t tub of water and add the 10 weights (10 people). During this time, we discussed what was working, what was not working and shared ideas for improvement. There was a table set up with extra supplies so students were able to improve and retest.
This guy tested and improved five times! That's five iterations of this ultimately successful raft!
The sharing for this design challenge was rolled over into the next challenge as students planned and and designed sails that would catch the wing and move the raft.
Part 2: The Sail
I chose, I Face the Wind, by Vicki Cobb to kick off discussion of wind. We went to the garden, to observe the wind and even though wind can not be seen, students observed evidence in tree branches, plant leaves, clouds and the anemometer.
We discussed different ways to 'catch the wind'...shopping bags, wind socks, kites and sails.
Once again, I used a Nearpod presentation to help students think about the possibilities. They were introduced to the challenge, viewed pictures of many different kinds of sails, considered possible materials, shapes and sizes. They imagined/drew what they thought would make a good sail for their raft.
We investigated the materials at school. We used a zip line, a fan and paper sails to draw conclusions about size and shape.
We tested different types of materials using a tub of water and students completed this chart.
Armed with information learned during the materials investigation, students went home to plan with their families using this planning sheet.
On Thursday evening, students and families arrived at school for Family Engineering Night where they built, tested, improved, retested and shared their sails.
The Raft Regatta
These videos show the 'Raft Regatta'. The kids were so excited and so proud to share their rafts with their families, their friends and their teachers. It was suggested to me, by a student, to take a 'slow-mo' video...good call! Check out the level of engagement on the faces of our youngest engineers in the last video!