Students can use a wooden ruler and a cylinder such as a cardboard tube or a can to make a simple lever. Tape the ruler perpendicular over the cylinder, which will be the fulcrum. Put a small object such as a block or rubber eraser on the end of the ruler that is on the table. Press the opposite end of the ruler to lift the object off the table. Invite students to move the fulcrum closer to one end and examine if the object is easier or more difficult to lift.
Create an inclined plane using a board propped up on one end. Place a large rubber band around a heavy object such as a book and tie a string to the rubber band. Ask students to lift the book by the string and then pull the book up the inclined plane. Compare how easy or difficult it was to lift the books with or without the inclined plane. Adjust the slope of the plane and invite students to repeat the exercise to determine if the slope of the inclined plane affects the difficulty of lifting a heavy object.
Toy cars are a great way to explore wheels and axles. Show students how the wheels are attached to the car with an axle. Ask students to push the car on its top and then push the car on its wheels and compare the distance the car traveled. Have students brainstorm other objects that contain wheels and axles, such as wagons or lawn mowers, and discuss how the wheels help those objects move.
Screws are actually made up of an inclined plane wrapped around a cylinder. To demonstrate this to students, have them cut a square from corner to corner to create an inclined plane. Tape one side of the triangle to a pencil or other cylindrical object and wrap it around until all of the paper is wrapped. Students will observe the edge of the inclined plane that became part of the screw. Ask them to compare this simple tool to the inclined plane and discuss how people might use screws in everyday life, such as to construct furniture.
Provide students with two square blocks and two triangular blocks of different widths as wedges. Invite them to place the two square blocks side-by-side and push one of the triangular blocks' point in between the two blocks. Measure the distance that the square blocks moved from each other. Repeat with a triangular block of a different width and measure the distance the blocks moved again. Compare the distances to see how the width of the wedge affected how the blocks moved.
To demonstrate how a pulley works, place a broom handle between two desks and attach it to the tops of each. Tie one end of a rope to the broom handle and then loop the free end of the rope through the handle of a jug filled with water to make it heavy. Loop the free end of the rope over the broom handle again and pull down to lift the heavy jug. Then ask students to loop the rope through the jug's handle and over the broom handle again to create a double pulley. Pull the free end of the rope again to lift the jug and compare if it was easier or more difficult to lift than with a single pulley.