Simple+Machines+6-8

Lesson Objectives By the end of this lesson, students should be able to:
 * Identify the six simple machines
 * Understand how the six simple machines function
 * Know that complex machines are made from two or more simple machines
 * Build simple machines and attempt to build complex machines



Engage: Activate Prior Knowledge; Generate Interest

Stimulate Interest

Display several simple machines to the class. Introduce the items as their machine type, rather than their common name. For example, display a hammer and say, “This is a lever.” Display a knife and say, “This is a wedge.” Students will likely be surprised to hear these simple objects referred to as machines. Ask students, “I wonder why we could say that a hammer is a lever? What makes something a lever? What makes something a machine? What are some other questions we could ask about a machine and its parts?”

Explore: Allowing Students to Experience Content

Post the essential questions that constitute what students will be learning. Students may read them or you may wish to read them aloud together.
 * What is a lever?
 * What is an inclined plane?
 * What is a wheel?
 * What is a pulley?
 * What is a wedge?
 * What is a screw?
 * What is a complex machine?

Divide the class into 6 groups. Assign each group a Getting To Know Passage for one of the following: [|lever], i[|nclined plane], [|wheel], [|pulley], [|wedge], [|screw] E ach group should become "experts" on their assigned simple machine. After about 15 minutes rearrange the class so that each group has a member from one of the expert groups. Have the new groups work on answering the essential questions in their journals with the experts explaining their machine to the rest of the group.



Next, assign for students to view or show the following video segments. Students should take notes on each video segment. Briefly pause between each video segment and discuss examples from life of the three simple machines. After viewing the video segment [|Lever], have students draw a lever and label the fulcrum. After viewing the video [|Inclined Plane], have students think about other locations in school that use an inclined plane (such as a wheelchair ramp).You can ask the class to share the locations they came up with or have them share quietly with a partner. After the video segment [|Wedge], have students scan the room to see if they can see any examples of wedges. They can share aloud with the class any examples that they find. Next, the video, [|Wheel and Axle], then ask students to brainstorm at least five ways that we use wheels every day. Then show the video segment [|The Pulley]. After this video segment, instruct students to create a simple drawing of a pulley to demonstrate their understanding. Next, show the video segment [|Screw], and, in addition to having students write down an answer to the Essential Question, also have them write a sentence to explain why screws are important. Finally, show the video segment [|Complex Machines]. After viewing this video segment, have students work with a partner to scan the classroom and find three examples of complex machines.



Complete as many of the following Hands-On Activities as possible.

Hands-On Activity [|Investigate Inclined Planes] Hands-On Activity [|Investigate Pulleys]. Hands-On Activity[| Investigate Screws] Hands-On Activity [|Investigate A Wheel and Axel] Hands-On Activity [|Investigate Wedges] Hands-On Activity [|Investigate Levers]

Explain: Firm Up Understanding; Allow Students to Explain What They Know

Instruct students to explore the interactive glossary terms [|balance], [|fulcrum], [|inclined plane], [|lever], [|mechanical advantage], [|pulley], [|screw],[| simple machine wedge], and [|work]. After students have explored these glossary terms individually, instruct them to pair up with a classmate and informally quiz each other on the definitions to the words.



Complete the Hands-On Activity [|Build a Simple Machine].

After completing the Hands-On Activity, bring the class back together as a large group and run through each Essential Question. Have the group that built each specific machine describe it and provide a real-life example of that simple machine. Other groups should listen when it is not their turn and compare answers with their notes. Then, ask all students to spend a few minutes with a partner to brainstorm at least five examples of complex machines. Remind them that complex machines do not always need a motor. After brainstorming, allow several students to share. Finally, discuss why simple and complex machines are so important for humans.

Elaborate: Allow Students to Apply What They Know

To help students understand more about one specific simple tool, the screw, instruct them to complete the Exploration [|Turn of the Screw]. This Exploration examines how easy or difficult it is to turn different screws in different wood types. Prior to this activity, students may not have realized that screws can have different thread patterns. Ask the class to think back to the screw that was created in the Hands-On Activity of this lesson, and ask them how they could modify it. What would more threads on the screw do? Fewer threads? You may elect to omit the student worksheet during this Exploration, but you should allow students time to explore the many possibilities.



Project Ideas: To help your students apply their understanding of types of simple machines, you may wish to have your students complete some or all of the following projects. The time required to complete each project will vary; some may require students to work outside the classroom.
 * Have students conduct research on Rube Goldberg machines. Rube Goldberg was a famous cartoonist and inventor who made intricate and detailed machines to perform simple tasks, like brushing teeth or turning a doorknob. You may wish to show students the video segment [|Work, Energy, and the Simple Machine: Compound Machines]. Play from 8:00 to 10:20 for good explanations of Rube Goldberg machines. Have students design their own Rube Goldberg machine. It should include at least two simple machines. Students should turn in a detailed illustration plus a paragraph explaining the function of their machine.
 * Have students conduct a complex machines scavenger hunt at home. Challenge them to find at least ten different complex machines. They should write a list of all the complex machines they find, and then pick one to describe. To describe it, they should create an illustration of it, identify what simple machines are involved, and write a paragraph to explain how the simple machines work together.
 * Have students conduct additional research on one of the simple machines. They should research its history, common applications, variations, and any other information (levers, for instance, have three types of classes). Students should compile their findings in a report, complete with illustrations, to turn in for a grade or display in the classroom.
 * Challenge students to invent a complex machine using their knowledge of simple machines. They should first identify a simple problem to solve (for instance: I can’t reach the hook for my towel when I get out of the shower, or I can’t reach the light switch after I’m already in bed), and then design a complex machine to solve that problem. For an extra challenge, have students construct their complex machine.

Evaluate: Check for Understanding

Have students complete any/all of the following BCR's:
 * [| Inclined Plane]
 * [|Levers]
 * [|Pulley]
 * [|Screw]
 * [|Wedge]
 * [|Wheel]