Make a paper propeller to represent a boat motor or an airplane engine. A child can use it to power an imaginary vehicle crafted from a large cardboard box. Paper propellers come together quickly and use minimal resources. Even a twin engine aircraft can be properly equipped in a matter of minutes.
Fold a sheet of construction paper lengthwise, then across the width into quarters.
Cut into four lengths with rounded tops, all at once.
Cut rounded slots into the bottoms that will fold into stems.
Tape the stems together to shape a cross.
Make a diagonal fold in the same direction on all four blades.
Find a circular cap or container that covers the stems. Use that to trace over a folded piece of paper and cut out two circles to make a hub.
Place the circles on either side of the center of the stem crossing. Tape them on between the blades.
Stick a push pin through the center of the hub and wiggle it from side to side to make a loose hole. Stick the pin to a pencil or imaginary engine. Blow on the propeller to spin.