Discuss how air pressure is involved in each situation. Illustrate each situation on the board and use arrows to show air pressure. The air inside of the balloon actually has nothing to do with the cups sticking. The gas inside the cup spreads out as much as it can to fill the new space, reducing the pressure. The balloon forms a barrier that keeps the air from mixing, and the high pressure outside the cups forces the cups to stay on the balloon.
Human bodies have trouble adjusting to rapid changes in pressure.
Your ear pops when the adjustment is made. Language Arts Connections Assign students to watch or listen to weather report on the television or the radio. Ask them to listen for terminology that they know. In class, have students compare the information in groups. Ask them if there was any terminology that they did not know.