4th Grade: What is a simple machine?
A simple machine has no or a few moving parts. It makes it easier to do work and move objects.
RAMP (Inclined Plane) makes it easier to move things up or down. Examples: a ski slope, a sliding pond
LEVER: a board on a fulcrum—lifts or balances things: examples: see-saw, pan balance
WEDGE: examples: axe, saw, knife, doorstop
SCREW: examples: light bulb, lid,
WHEEL & AXLE: examples: doorknob, a water faucet
PULLEY : a rope on a wheel which lifts things
examples: elevator, curtains, flagpole