What You'll Need:

water
regular laundry bleach
white school glue
a sponge paint brush
the help of an adult

What to Do:
(Note: If you want the sand dollar to retain its natural color, you can skip step two)

1. Soak or rinse your sand dollar in fresh water until the water is clear. This will remove any remaining spines, residue, and sand from the test. Handle the sand dollar carefully!
2. Have an adult make a solution that is 3 parts water and 2 part bleach. Soak the test in it for about 10 minutes. The bleach solution will disinfect and clean the test. It's important not to use too much bleach or to soak the sand dollar for too long. Bleaching weakens sand dollars, and too much exposure will cause them to crumble.
3. Rinse thoroughly, and dry completely.
4. Make a solution of equal parts of water and glue.
5. Carefully brush the solution over both sides of the test and allow each side to dry. This will harden the test, making it more durable. Your sand dollar is now ready for display!