• Assess students’ Machines in Action worksheets to see how each student performed on the activity. Provide feedback or give examples where needed on the worksheet.
• Assess students’ ability to demonstrate how a lever works.
• Collect the Machines in Action 2 Worksheet for individual assessment.
• Observe students in their “simple machines” groups. Determine if students are performing the activities accurately and answer any questions they may have.

Activity 1: Hunting for Machines

Explain to students, “A simple machine can be as small as a stapler, pencil sharpener, wheelbarrow, or our flag pole outside of school. Some simple machines are so simple that we wouldn’t consider them a ‘machine.’ When two simple machines work together, we call it a complex machine.”

Have students look around the classroom for examples of simple machines. Allow students to share their examples as you record responses on the board or chart. After the examples are placed on the board, have students classify the examples as one of these simple machines shown in the pictures: inclined plane, wedge, screw, lever, pulley, or wheel and axle.

After you feel that students have grasped the concept of simple machines, have them complete the following hands-on activity to reinforce understanding of the different types of simple machines. Give students the Simple Machines Resource Chart worksheet (S-3-4-3_Simple Machines Resource Chart.doc) as a way to help them understand some of the different simple machines and what they do. Instruct students that they will be moving to each station and investigating a simple machine. They should take with them the Simple Machines Resource Chart worksheet (S-3-4-3_Simple Machines Resource Chart.doc). They are to complete the chart as they travel through the stations. Note: Before students rotate through the stations, go over safety rules and demonstrate how to work with each simple machine.

Students should be divided into six groups. Each group should start at a different simple machine station. Students rotate stations every 5-7 minutes:

• Lever Station: Students see different examples of a lever. They are able to pick them up, feel them, and see them in action. Examples of a lever that can be displayed are a fork, a baseball bat, scissors, and a stapler.
• Inclined Plane Station: To demonstrate an inclined plane, a group of students can compare lifting a moderately heavy box from the floor to the table, with and without a ramp.
• Wheel and Axel Station: Students see different examples of a wheel and axle. They are able to pick them up, feel them, and see them in action. Examples of a wheel and axle that can be displayed are a rolling pin, roller skates, and an egg beater.
• Screw Station: Students try to screw a nail into a piece of wood. The nail must be prescrewed, so it is easy for students to perform this task. If students are not able to use a screw and screwdriver, you can set up jars for students to screw the tops of the jars on and off.
• Pulley Station: You can construct a pulley in the classroom by tying one end of the rope around a bucket or plastic pail, and hanging the other end of the rope over the door. Students pull on the rope and watch the bucket lift from the floor. Note: assign a student volunteer to keep an eye on the door to avoid someone opening the door during the demonstration.
• Wedge Station: Students see different examples of a wedge. They are able to pick them up, feel them, and see them in action. Examples of wedges that can be displayed are a shark tooth and plastic knitting needles.

Activity 2: Complex Machines

Begin the activity by reading Click, Rumble, Roar: Poems about Machines by Lee Bennet Hopkins. Discuss the book with students and ask for examples of machines from the book. Record responses on the board and ask students whether these are examples of simple machines. Introduce students to complex machines. Show students pictures of a car, bulldozer, and bicycle. Explain to children that a complex machine is two or more simple machines put together.

Give each student a copy of Machines in Action 2 worksheet (S-3-4-3_Machines in Action 2 Worksheet and KEY.doc). Take students around the school so they can fill in their Machines in Action worksheet with the different types of simple machines and complex machines they see around the school. Students can also work in pairs or groups, and you can provide them with discussion prompts so they can be explorers. After students finish the activity and worksheet, have them present their findings to the class. Students may also write down other examples of machines that were found by their peers.

Extension:

• Students who may need an opportunity for additional learning can create a simple machine mobile using yarn, paper clips, a coat hanger, and magazines.

Prior to the activity, precut several pieces of yarn 20 to 22 centimeters long. Students should draw or identify simple machines from pictures in a magazine. Their Simple Machines Resource Chart (S-3-4-3_Simple Machines Resource Chart.doc) could also help students identify machines. Give students the following instructions:

1.      Tie one end of each piece of string to a paper clip and hang the paper clip from a wire or plastic clothes hanger.

2.      Select pictures of machines to draw or cut out.

3.      Tie the pictures to the yarn.

• Students who might be going beyond the standards may select one complex machine. On poster board, they can describe which simple machines came together to compose the complex machine. They should also describe what the machine is and how it helps people work.