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Washing Hands


This activity focuses on germs and learning how to prevent the spread of germs.


  • Two potatoes cut into chunky slices and stored in salt water
  • Six Ziploc sandwich bags
  • Soap
  • Poster board or paper for signs
  • Wall space to display experiment at eye level

Additional Resources


  • Little Rabbit's Loose Tooth, by Lucy Bate; ISBN 0517551225
  • Germs Make Me Sick!, by Melvin Berger; ISBN 0064450988

Background for Teachers

Germs can be found everywhere; they are just so tiny that we can't see them. There are good germs and bad ones. Two kinds of germs that will make us sick are called bacteria and viruses. We can get these germs from other people who cough or sneeze and don't cover their mouth. We can also get germs from not washing our hands long enough with soap.

Intended Learning Outcomes

4. Develop physical skills and personal hygiene.
6. Communicate clearly in oral, artistic, written, and nonverbal form.

Instructional Procedures

Invitation to Learn
Have soap, Ziploc bags, and potatoes on the table.

Instructional Procedures
Talk about germs. Talk about where they are found and how they are spread. Discuss how you can help prevent germs from spreading. Talk about why it is important to use soap.

  1. Students will be divided into three groups.
  2. Each group will handle two pieces of peeled potato, then place them into a separate sealed Ziploc bag.
    Group 1—Will not wash their hands
    Group 2—Will wash with cold water
    Group 3—Will wash with soap and warm water
  3. The bags will then be placed on a wall at an eye level for the students to watch them for the next week.
  4. The growth will be charted on a picture graph next to the Ziploc bags.
  5. Students will graph (on a separate graph) their prediction of what might happen.
  6. At the end of this experiment, your results should be quite different. The potatoes that were touched by the unwashed hands should have a greater bacterial growth than those touched by hands washed with soap.


Talk about germs in your mouth

  • Apple experiment
    1. Take two apples.
    2. Poke a nail hole in the side of one of the apples.
    3. Place each apple in a separate paper bag for a week.
    4. Take both apples out and look at them before cutting them in half, the one through the nail hole.
    5. Talk about what happened to the apple. Compare it to our teeth and when we get cavities.
  • Egg experiment #1
    1. Use a hard boiled egg and compare the shell to the enamel on our teeth. The enamel protects the tooth just like the shell protects the egg.
    2. Place the egg in vinegar for a few minutes.
    3. Take the egg out and poke an indentation into the side of the shell. Compare it to a cavity.
    4. Talk about how it is important to clean our teeth.
  • Egg experiment #2
    1. Take two boiled eggs.
    2. Place one in cola overnight and the other in vinegar. The cola will stain the shell and the vinegar will dissolve the shell. Compare your finding to what might happen if you don’t brush and floss your teeth.
  • Demonstrate how to brush your teeth.
  • Paint with a toothbrush.
  • Talk about sneezing and coughing.
  • Make a sneezing/coughing face.
    1. Have each student make their face on a oval piece of paper.
    2. Trace both hands on a paper and cut it out.
    3. Last glue on the hands at the bottom of the face and a tissue under one of the hands.
  • Play Find Your Potato game.
    1. Give each child a potato right out of the bag.
    2. Let each child study their potato.
    3. Place all of the potatoes in a big bowl.
    4. Have each child try and find their potato.
    5. Repeat activity, this time have a neighbor find your potato.
    6. Talk about how everyone is different.

Family Connections

  • Draw fun pictures of washing our hands to hang up around the house.
  • Have students explain to a family member the proper way to wash hands.

Assessment Plan

  • Watch how the students graph the growth on the potatoes each day.
  • Observe students to see if they are doing a better job at washing their hands after the lesson.
  • Observe if the students are more health conscious when they have a runny nose or are sneezing around others.

Created: 09/08/2004
Updated: 10/31/2022