Divide a blank sheet of paper into at least three columns. Label each column as follows: "Experiment 1," "Experiment 2" and "Experiment 3." Write the following words at the top of each column, respectively: "Fresh Water," "1 Cup Salt Water" and "2 Cups Salt Water."
Fill a bucket 50 percent full with fresh water. Place a standard light bulb into the water. Allow the bulb to settle and float. Measure the height of the object --- from the surface of the water to the top of the bulb. Write down the measurement in column one.
Remove the light bulb. Dry the light bulb. Add 1 cup salt to the bucket. Stir the bucket until the salt is thoroughly mixed.
Place the light bulb back into the water. Allow the bulb to settle and float. Measure the height of the object --- from the surface of the water to the top of the bulb. Write down the measurement in column two. The bulb should be floating higher due to the increased water density created by the salt.
Repeat the previous two steps for column three. Discuss with students the comparisons between flotation measurement and water density. Continue the experiment with greater quantities of salt or different objects.