A seesaw rests on a bar in the middle, so one end rises when the other goes down. What simple machine is it?

A rower pulls on the top of an oar that turns against the edge of the boat. What simple machine is the oar?

A rope runs over a grooved wheel at the top of a flagpole to raise the flag. What simple machine is that wheel?

A window blind goes up when a cord is pulled over a small wheel inside the top rail. What simple machine is that?

A round doorknob is fixed to a thin metal rod that turns with it. What simple machine is the doorknob?

A driver turns a large round steering wheel, and a thin shaft at its center turns too. What simple machine is it?

A flat, slanted walkway runs from the sidewalk up to a doorway for wheelchairs. What simple machine is it?

A playground slide is a smooth, flat surface that slants from the top platform down to the ground. What simple machine is it?

A knife blade is thick along the back and very thin along its cutting edge. What simple machine is the blade?

A doorstop is a small block that is thick at one end and thin at the other. What simple machine is it?

A metal fastener has a ridge that winds around and around its post. What simple machine is it?

A jar lid twists onto ridges that wind around the top of the jar. What simple machine is at work?

A staircase winds around a center post as it climbs from one floor to the next. What simple machine does it copy?

A rope over a fixed wheel above a well lets a person pull down to raise the bucket. What does that wheel do to the force?

Turning the wide handle of a faucet also turns the thin rod inside it. What does the wide handle do?

Amir lifts the long handle of a bottle opener to pop a metal cap off a bottle. What does the opener do?

A worker taps the flat top of a chisel, and its thin edge splits the wood apart. What does the chisel do to the force?

Turning a bolt many times pulls two bed frame pieces tightly together. What does the bolt do to the force?

A mountain road winds gently back and forth instead of climbing straight up the slope. Why is that easier for a truck?

A nail's pointed tip pushes the wood apart as a hammer drives it in, so the tip works as a wedge.

Nia slips the claw of a hammer under a nail head and pulls back on the long handle. What does the handle do?

A loaded cart is easier to drag along the ground than to roll on wheels and axles.

A screwdriver with a thicker handle turns a stubborn screw more easily than a thin one. Why does the thicker handle help?

A pry bar with a longer handle lifts the same heavy stone with less force.

Marco stands on the barn floor and pulls a rope that runs over a wheel on a high beam to raise hay. Why is pulling down easier?

A gangplank slanting up to a boat deck lets a person roll a barrel aboard using no force at all.

Rosa stands on a roof and must raise a heavy bundle of shingles from the ground below. Which simple machine helps her most?

Which simple machine is best for splitting a block of firewood down the middle?

Sam must move a heavy barrel from the ground up onto a platform without lifting it. Which simple machine should he use?

Which simple machine holds two boards tightly together so they cannot pull apart?