The typical course of study for fifth-grade science includes the scientific method and inquiry. Simple machines--the lever, wheel and axle, pulley, inclined plane, wedge, and screw--provide many hands-on opportunities to practice the scientific method. Because everything mechanical begins with at least one of these six simple machines, students benefit from projects that help them understand the purpose of each.
First, help the fifth-grade students recognise the simple machines they use every day. In groups or individually, instruct them to go on a scavenger hunt to find simple machines at school. They can also do this exercise at home, but they should bring back a form listing all the simple machines they find. Remind them not to overlook any possibilities. For example, a skateboard qualifies as a wheel and axle, as does a pizza cutter. A light bulb qualifies as a screw.
Students can make a pinball game using two simple machines--a lever and an inclined plane. Using a shoebox lid, they can attach spools or parts of an egg carton to the top on one end. When they flip the lid over, it becomes an inclined plane. A lever attached in one lower corner will launch the marble. Next, they must create an obstacle course for the marble. Students can experiment with different sizes of lids, different sizes and materials for levers, and different obstacles courses.
Even the most reluctant young scientist could enjoy building a catapult. Challenge the fifth-grade students to make this lever machine with various materials. Students should research designs and create working models. If possible, provide materials to complete projects at school, or ask them to complete their catapults at home. Have a catapult contest to see which projected the farthest. Discuss the materials used, designs and projectiles.
Don't overlook Tinker Toys when choosing materials for simple machine projects for fifth-graders. Students can build several simple machines using a complete Tinker Toy set or just components of the set. With the wheel and axle components, they can build a Tinker Toy Ferris wheel or windmill. Each set also includes pulleys. These can make flag poles, sails for a boat, cranes or a moving clothesline. Students can also make a catapult. After they master the basic designs, encourage them to expand on what they've learnt.