To explore the parts of a system and develop students’ understanding of the interactions between those parts. To engage in troubleshooting and design related to systems.
This lesson is the first of a two-part series on systems. Students should understand that how a system is able to function is dependent on the amount and type of parts and how they are assembled. Research suggests that students tend to examine the separate qualities of the objects within the system rather than seeing the interaction between the objects. Students need to start to understand that a system is actually an interaction of parts. They need to move away from the notion that the properties of a system belong to the individual parts.(Benchmarks for Science Literacy, pp. 355-356.)
Elementary students tend to believe that a system must be doing something in order to be a system or that a system that loses a part of itself is still the same system. Also, students tend to interpret phenomena by noting the qualities of the separate objects rather than by seeing the interactions between the parts of a system. Children do not appreciate that parts come together to make a whole that has properties that the parts do not. For children, wholes are like their parts. (Benchmarks for Science Literacy, pp. 355-356.)
In Systems 1: Simple Machines, students take a closer look at a variety of simple hardware devices. Students observe the interactions between the elements of the devices, through both hands-on and Internet exploration. Developing the concept of a system helps establish a framework for understanding ideas related to nearly all other benchmark topics.
Systems 2: Systems, Up, Up and Away! is designed to allow students to explore how changing parts or amounts will impact the properties of a system.
Preview the online activities used in this lesson and gather required materials (listed on the websites):
Before starting the Motivation, distribute the Gadget Breakdown student sheet. Students will use the top part of the sheet for this activity.
Visit the Exploring Leonardo website, designed by Boston's Museum of Science for the Science Learning Network, with your students. Provide students with the Sketching Gadget Anatomy sheet and ask them to complete the classroom activity .
In this activity, students are divided into small groups and presented with a small hardware device such as an egg beater, can opener, cork screw, car jack, garlic press, ice cream scoop, salad tongs, nutcracker, monkey wrench, hand drill, Vise-Grips, the mechanism from a music box, wind-up toy, pencil sharpener, or stapler. Each member of the group is responsible for drawing and labeling what they see as the essential parts of the device. Students can use the box provided on the Gadget Breakdown student sheet to do so.
Identifying the parts of a system
Ask students to name what they consider to be the most important parts of the device. Have students answer these questions about each of the parts on their student sheets:
- What does this part help the device do?
- What can this part do on its own?
- What can this part do when combined with other parts?
Have students share their findings. Ask questions like: What are the essential parts of the device? Are there parts that are common to many of the groups' devices? Create a chart listing these parts, using whatever terminology the students have used.
Using the Parts of a System student esheet, students should now visit (or view printouts of) Exploring Leonardo's Inventor's Toolbox: The Elements of Machines and/or The Franklin Institute's Simple Machines to learn more about simple machines. They should be sure to took for parts found on their group's device.
Review group sketches from the previous activity, asking questions such as:
- Which simple machines are part of your device?
- What is the function of each?
To extend this activity, students should visit Gadget Anatomy, at the Boston Museum of Science, to take a quiz on the elements of several hand-powered tools. Encourage them to think about how each part moves and makes the other parts move as the tool does its job.
Now, using the student esheet once again, students should vist the How Stuff Works site. Once there, students should do a keyword search to look for devices with elements similar to those in the gadget that they sketched earlier. Have students identify one such device and answer these questions on the Parts of a System student sheet:
- What is the function of this system as a whole?
- What are the essential parts of the system?
- What are the functions of these parts?
- Do they perform the same function in both devices?
- Would this device function if one of the elements were removed? Which element could be removed?
- Could the same basic elements be organized a different way to perform different functions?
- Is it possible to enhance this device by adding another element?
Allow time for students to share their ideas in small groups.
Have students work in teams to design their own system using some or all of the parts that they have identified. Students should decide what the system's function will be and then sketch the essential elements of the device. (Visit Be Inventive!, at the Exploring Leonardo site, for examples of both historical and modern design challenges.)
Students should be presented with a wide variety of materials, including: Tinker Toys®, Legos®, wheels, dowels, foam board, plastic containers or scraps, miscellaneous junk, toy pieces, aluminum foil, heavy cardboard, glue, tape, string, and rubber bands.
When students have completed their designs, have each member of the group complete a journal entry in which they document their work, sketching and labeling the parts in the final design. Students should also write about any problems that arose or any improvements that they would make if they had access to unlimited materials. Have students present their completed designs to the class.
Follow this lesson with the next one in the Systems series: Systems 2: Systems, Up, Up and Away!
Give students a broken hardware device that can be disassembled. Have students troubleshoot by exploring a variety of similar devices, either in the classroom, at home, or at the How Stuff Works site.
Have students attempt to assemble a simple kit without the proper instructions in order to emphasize the importance of the proper arrangement of the parts. Students should generate their own list of clear, ordered steps for proper assembly.
Visit Leonardo's Mysterious Machinery, at the Exploring Leonardo site, to see eight examples of da Vinci's design sketches. Have students guess the function of each machine based on its elements. How similar are these machines to their modern-day counterparts? Can they identify the elements of the machines?