Not So Simple Machines PBL

This month in 5th grade STEM, we're learning about simple machines and engineering as part of our Ancient Commerce PBL. Together with the 5th grade Chinese language, math and English teachers, we're creating an interdisciplinary unit focused on how commerce affects culture. As students learn about the history of trade along the silk road in Chinese language class, we are introducing in STEM how simple tools could have been used to transport goods along the way. In the end, they built their own complex machines that needed to carry 200g weights over a "valley" (made of styrofoam blocks), and tell a story in English about this part of the journey on the silk road. It's taken a lot of hot glue and cardboard, but they learned some great engineering skills along the way!

Working with other teachers from the grade level has been a great experience for this PBL. We decided to organize the unit around the driving question "How does commerce change culture?" We wanted students to focus on collaboration and communication, and so for each building challenge, they are working with a different partner in class. Then, they need to record the machines that they build in their weekly journey log. My STEM partner Sander and I decided to use OneNote as a template for their individual journey log, which serves as a great collection of their work and a place for them to reflect on their engineering. By recording each mini-challenge in the weeks leading up to their final big challenge, students also started crafting a "story" of their journey. In English, they practiced writing traditional tales that weave together historical knowledge of the Silk Road and the scenarios we created for their engineering challenges. Although it's still hard to find enough time to plan with all of the other teachers together, it's been a great experience to be able to make these connections when we can.

Over the six weeks in STEM, students learned about each of the simple machines one by one. They do a small mini-challenge based around a silk road scenario, such as needing to lift a load off a cart with a pulley or make a catapult to defend against invaders. For each challenge, students had to follow the engineering design cycle (Ask, Imagine, Plan, Create, Improve). Most of the materials were common, low-cost items like chopsticks, cardboard, popsicle sticks and rubber bands. For the final challenge, students needed to make a complex device that would carry 200g over a 10cm gap, but also retract afterwards. We used this design packet to help them craft their ideas :

G5 Unit 4 Final Challenge Design Packet.pptx

Download PPTX • 1.17MB

There were a few cases when students ran out of time before they could finish their machine for the day, particularly when we built the Archimedes Screw. But I always let students keep their constructions in the classroom, and they were able to work on it during recess or break time to finish it later. Overall, they had a blast doing so much hands-on construction work, and they learned great problem solving skills along the way. This will definitely be one of my favorite units to try again next year!