As our Grade 3 students investigated ‘How the World Works’ we wanted to find out ‘What cool things we could make using Newton’s Laws of Motion?’ After several investigations into Newton’s laws and a look at simple machines, we began to look at how people put simple machines together to make interesting things. This inevitably led us to Rube Goldberg and a plethora of machines designed based upon his wacky ideas.
After looking at some amazing examples- our favorites included OK Go’s ‘This Too Shall Pass’ and Joseph Herscher’s ‘The Page Turner’– and discussing the many simple machines and Newtonian Laws at work, we set to our design our own Rube Goldberg-style machines.
First, each student chose a simple task like turning on a tap, flipping a light switch or ringing a bell. The students then designed their machines on paper focusing on the sequence of simple machines.
Initially, I think the students were confused by the complexity of the examples they saw, and tried to design equally complex machines which led to some serious design problems. Perfect! Once the kids built their machines they got to experience how these design flaws (which seemed to work well on paper) were very difficult to pull off.
We set aside a whole school day to build, describe and share our machines among the Grade 3 classes. When describing their machines we asked our kids to focus on the concepts of ‘function’ and ‘connection’, and we asked them to use specific vocabulary related to Newtonian mechanics (eg. gravity, force, kinetic energy and the like.) Although very few of the machines were successful, the experience of trying to build a complex machine was very valuable and this students were able to both identify simple machines and the forces at work in them.
Our class spent time the next day reflecting on the machines that worked and discovered a few important ideas. First, we found that successful machines were all made by connecting simple machines that worked well. Second, successful machines were designed backwards; that is, the students started with the end of the machine and worked toward the beginning.
After reflecting, we set out to redesign our machines for another Rube Goldberg Day. This was a key move. Giving the kids another opportunity to go back to the drawing board, think carefully about what worked and what didn’t, and encouraging the kids to have another go at their machines led to a deeper understanding of how to connect simple machines into a more successful complex machine.
We had our second Rube Goldberg day yesterday and virtually every machine was both interesting and successful. We had plant waterers, t-shirt painters, coin flippers, bell ringers, stapling machines, chip dispensers, goal-scoring machines, and they all worked! Parents and other classes who viewed the kids’ machines and listened to their detailed explanations of the forces at work were blown away not only by the complexity of the machines but also the feverish enthusiasm of the students who built, displayed, and described them.