What is needed

What to do

What is happening

When the balloon is rubbed against something, it develops a charge from the friction. Since the balloon is an insulator, the charge will stay right where it is. You probably charged up one side of the balloon more than the other, so when you bring it toward the monitor, the balloon will rotate: if the balloon is charged up the same as the monitor, it will turn away. If it is charged up opposite to the monitor, it will turn toward it. This will happen over and over, so you can draw faces on the balloon to mark the sides.

Try turning your monitor on and off while you do this. Your monitor makes a lot of static charge, and it changes when turned on and off. Does this change the attraction or repulsion of the balloon?