In Simple Machines students become familiar with several simple machines through exposure in day-to-day life at an old-time farm. Students understand that they can move things on wheels, but they probably have not considered that wheels are attached to axles and that when one turns, so does the other. Nor have they considered how a wheel and axle can make a task easier. Students have certainly experienced inclined planes but likely have never considered how a ramp contributes to the ease of lifting something upward. So, students have some basis for understanding what a simple machine is, and this unit allows them to explore the classic simple machines more thoroughly.

In this unit, students will identify simple machines—the ramp (inclined plane), wheel and axle, pulley, lever, wedge, screw, and gears. Students will explore where these devices are found and experience how they can make a given task easier. Students will also learn that simple machines are combined to make compound machines, which themselves can be familiar and be operated simply.

Scientists, including biologists, zoologists, geologists, and climatologists, study how living things affect the land, air, and water. This series of lessons incorporates learning goals that support scientific principles and practices, such as asking questions, arguing with evidence, analyzing and interpreting data, recognizing cause and effect, and planning and carrying out investigations.