
 gallon jug
 water
 water basin
 rubber tube
 measuring cup
 Fill a gallon jug with 16 cups of water.
 Put about an inch of water into a wash basin.
 Turn the jug upside down into the wash basin. The water in the jug won't come out.
 Put a rubber tube into the gallon jug.
 Now, take a deep breath and blow on the tube.
 Measure the water by lifting the jug up and then pouring the water into a measuring cup.
 Subtract the amount you measure from 16 cups. For example, if there are 8 cups of water in the measuring cup, subtract 8 from 16.
 So, you'd have 8 cups of air in your lungs.
 Try this with your friends. Make sure you wash the tube with alcohol after each person uses it. See how much air their lungs can hold and see if you can answer questions like: do people who exercise hold more air in their lungs or does the size of your body effect how much air your lungs hold?

