Skin Sacks

Pre-K through Grade 2

Grade 3 through Grade 6

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Grade Levels Grades 1 and 2

Estimated Teaching Time

• Introduction and set up: 25 minutes
• Observation: three minutes each day
• Draw conclusions: 10 minutes

Interdisciplinary Connections

• Working cooperatively (Social Skills)
• Drawing faces on oranges (Art)
• Carrying out an experiment (Science)
• Testing hypotheses about treating wounded oranges (Science)

Objectives

Children will:

• Learn that skin helps keep germs out of their bodies.
• Learn the importance of treating injured skin.
• Start to learn how to design experiments.
• Develop observation and interpretation skills.
• Practice problem solving.

What Children Do

Children will use fruit to learn how their skin helps keep infection out of their bodies by comparing “wounded” oranges with “uninjured” ones. They will also see whether antiseptic and bandages make a difference by treating some of the wounded oranges. The class will then observe its oranges over several days and see which ones rot the fastest.

Materials Required

• Oranges, one per child
• Permanent markers, enough for class to share
• Resealable plastic baggies, big enough to fit whole oranges, one per child
• Plastic bandages, one per child
• Dry soil
• Skin antiseptic, one bottle for class
• Chart paper
• Optional Camera and film

Advanced Preparation

Put a teaspoon of dry dirt in each baggie to provide some mold and bacteria to promote quick rotting.

Suggested Sequence

1. Discuss what children think skin does for them, drawing on what they have learned in earlier lessons.
2. Hand out one orange to each child (keeping back two as controls). Let them draw faces on the oranges.
3. Demonstrate to the class ways they can wound their oranges with cuts, bruises or scrapes. However, do not allow them to pulverize the oranges.
4. Give some children the option of putting antiseptic and bandages on their wounded oranges. The others will be left untreated for a few days. Two oranges will be uninjured as a control. Each should be bagged in a plastic baggie with a little dirt in the bottom.
5. Group the treated, injured oranges (those with bandages and antiseptic) in one area, and the injured but untreated oranges in another, so results will be easy to compare between the two groups. Put the uninjured oranges in a separate group as well.
6. Ask children to predict what will happen to the three groups of oranges. Record their ideas on chart paper.
7. Each day children will observe what is actually happening. There should be a clear difference in which ones decay the fastest. Taking photographs will help with the discussion later and will make a great bulletin display.
8. In a week or so, when the oranges have decayed, ask children for their observations and explanations.

Check for Understanding

Ask the following questions:

• How were the oranges different in the two injured groups? Did bandages and antiseptic make a difference?
• Why were two oranges left uninjured?
• How does this experiment relate to you and your own skin?

Extensions

• Ask children to recall what happened when their own skin was cut or scraped.
• What stages did the cut go through? Ask them to make a series of pictures of the metamorphosis of a skin cut: reddening (if it became infected), swelling, scabbing, skin regeneration.
• What do they think happened at each of these stages?
• How does it relate to what happened to the wounded oranges?

Words to Share

• Antiseptic
• Bacteria
• Control
• Mold