This includes time for students to retrieve and review the assignment, read the background material, find and observe their subject, answer questions about their findings, and write their reports. You may wish to assign the step of finding and observing a subject as homework. Students conduct a simple investigation. Students employ simple equipment and tools to gather data and extend the senses. Students use data to construct a reasonable explanation of how simple machines work.
Students communicate investigations and explanations.
Students discover that the position and motion of objects can be changed by pushing or pulling. The size of the change is related to the strength of the push or pull. Technological solutions have intended benefits and unintended consequences. Some consequences can be predicted, others cannot. Students learn that people continue inventing new ways of doing things, solving problems, and getting work done.