Simple Machines Made Simple,’ which raised more than seven times its target on Kickstarter, wants to demystify mechanical engineering for kids. How do you explain the laws of physics to a toddler?

After learning about the lever, wheel and axle, pulley, inclined plane, wedge and screw, the students designed a future Hilltop playground, one that included examples of each simple machine studied.

When you push or pull with a simple machine, you are applying a force and doing work. And, if you get more force out of a machine than you put into it, then that machine has a mechanical advantage.