This trick is super easy to learn, and will impress everyone! All you need to do is to hold the orange part, with your fingers on the slanted part, and then pinch really hard. This motion will send the orange piece flying into the green piece. I suggest pulling the orange part out 1.5 to 3 cm before snapping it back.  The rubber band and washers are just to confuse the audience! The hook never actually touches the rubber band! To get the rubber band into the holes, I cut it so that is was more of a string than a band, then I put a twist tie on it, threaded the twist tie through, put the washers on both sides, then tied the rubber band on both ends.