Things You'll Need
Instructions
Tie both ends of the rubber tubing to form a circle.
Slip the tube of cloth over the circle. Slide it to the center of the rubber tubing.
Experiment. Have two friends each hold an end of the rubber tubing. Place a water balloon in the cloth. Pull the sling back a few feet and release it.
Use the tape measure to see how far the balloon traveled. Adjust the distance you pull back on the sling shot to ensure the balloon goes 100 to 200 feet.