In a 5-week online class, students in grades 2 – 4 learned about the seven best known simple machines — lever, inclined plane, wedge, screw, wheel and axle, gear, and pulley — through videos, on-camera demonstrations, discussion and hands-on activities. The purpose of the unit was to show how humans developed ways to make certain kinds of work possible, or at least easier, and how this small set of simple machines are the basic units used in most more complex machinery we use today. Students were asked to locate examples of simple machines around the house, and to draw or photograph those examples. Older students also constructed simple machines and demonstrated what they could do.  As a final option, students were encouraged to build Rube Goldberg machines at home, and to share them via video or on-camera demonstration.