This video shows you how to make a simple paper popper in three simple steps. Take a rectangular piece of paper and fold one quarter over. Fold it over once again in the same direction. Flip the paper over and make it into a square by folding again. Open out the side just a little bit, so that you can see the fold still inside. Sweep your arm down from a height really quickly and you will hear the sound of a "crack" as the paper pops on the way down. You can do the same thing again if you refold the paper back into its original folds.