Trace around a small plastic lid onto cardboard. Cut out the circle. Make designs on it with crayons or markers.
Ask an adult to help you thread a 4-foot-long piece of string through a needle. Push the needle through the center of the lid. Push it back through, making another hole right next to the first one.
Remove the needle. Tie the ends of the string together. Adjust it so there is an equal amount of string on both sides of the lid.
Make a hole in the center of the cardboard circle. With the design facing out, slide the cardboard onto the string on the bottom side of the lid. Push the circle inside the lid.
Hold each end of the string, and swing the lid in circles until the string on both sides is twisted. To make the lid spin, slowly pull on the string. Stop pulling to let the string wind in the other direction. To keep the lid spinning, alternate these motions.
Create different patterns on other pieces of cardboard. Spin each separately on the whirligig to see what they look like.