Teaching simple machines to inspire young engineers


“What is a machine?” We asked dozens of kids when researching Simple Machines. Machines use electricity, they said. Machines are big, complicated, metallic; they’re like dishwashers, windmills, or trains.

Next we asked, “What is the simplest machine you know?” Many kids named computers, tablets, and phones. Their answers surprised us, but they shouldn’t have.

Those machines are, after all, some of the simplest to use. As one 8-year-old said, “You just have to tap stuff and move stuff around by using your hands.” No mechanical expertise necessary.

Electronic machines are simple to use, usually, but they’re not simple to build. Nor are they easy to understand. We know that if we tap a tablet’s screen, then the app we want to use will open. But how does that happen? Even if we broke the device open and studied its parts, we wouldn’t learn much.

That’s the beauty of simple machines, and it’s why we teach them. They are as easy to use as tablets or computers, but they reward a young learner’s exploration in a way those other machines don’t.

Take the lever, a flat bar that pivots on a fulcrum. Seesaws are levers, and so are shovels. Anyone can perform quick tests to explore how levers help us. If we push on one side of a lever, the other side lifts up. If the side on which we push gets longer, it becomes easier to lift the other side. Easy!

Kids get this when they use simple machines. After playing with the lever in the Simple Machines app, one boy said his arm “would have given up” if he tried to throw as hard as the lever did. He could immediately see how the machine helped him as he applied force to it.

When kids study simple machines, they discover the fundamental mechanical rules at the heart of engineering. Each change they make to a simple machine causes a measurable change in the machine’s performance. This is a great way for kids to start thinking of themselves as scientists, ones who might some day be able to explain exactly how a touchscreen works.