To introduce students to microbes and help them understand how tiny they can be.
This lesson uses a book called Tiny Creatures: The World of Microbes by Nicola Davies with illustrations by Emily Sutton to help introduce students to microbes, their variety, and their sizes. This book was one of the winners of the 2015 AAAS/Subaru SB&F Prize for Excellence in Science Books. SB&F, Science Books & Films, is a project of the American Association for the Advancement of Science.
At this grade level, it is important for students to have many experiences with numbers, from simply having fun with numbers by taking part in counting games to using numbers to describe and name things. You should remember, though, that students in these grades may not be comfortable yet with using numbers to compare magnitude. So they should be kept to simple comparisons in observations: What is smaller or larger, what might be still smaller or larger, what is the smallest or largest they could imagine, and do such things exist?
Nicola Davies does a wonderful job of helping students use numbers to make these comparisons in her book. In Tiny Creatures, Davies tackles what is undoubtedly an uncommon topic for a children's picture book. In doing so, she demonstrates how a conceptually difficult idea can be effectively introduced to the very young. Davies makes an immediate connection to her readers, using their prior knowledge of big whales and small ants to convey how tiny microbes can be. She provides examples of their sizes and numbers, their varied shapes, their habitats, appetites, and how they eat. Throughout the book, Davies focuses on the basic essentials of the concept "microbe” in a text that is perfectly complemented by Sutton's charming illustrations.
In this lesson, you will read the book aloud to your students and discuss with them the concepts presented in it. The reading and discussion will be followed by an activity in which students are asked to draw some of their own comparisons based on the spreads in the book.
Ideas in this lesson are also related to concepts found in the following Common Core State Standards:
With prompting and support, ask and answer questions about key details in a text.
Use illustrations and details in a story to describe its characters, setting, or events.
Ask and answer questions about key details in a text.
Use information gained from the illustrations and words in a print or digital text to demonstrate understanding of its characters, setting, or plot.
Ask and answer such questions as who, what, where, when, why, and how to demonstrate understanding of key details in a text.
Identify the main purpose of a text, including what the author wants to answer, explain, or describe.
This book uses size and scale to introduce the idea of microbes. To prepare students for this, you may want to have a discussion about large numbers, like millions and billions.
Begin the lesson by asking your students these questions:
- How would you describe the size of a mouse? Of an elephant?
- How many mice do you think could fit on an elephant?
- But did you know there are things smaller than mice and bigger than elephants?
- Can you think of animals that are bigger than elephants? What are they?
- How many elephants do you think it would take to make up a whale?
- Fleas are smaller than mice. How many fleas do you think could fit on a mouse?
- Do you think there are living things even smaller than fleas?
As you go through these questions with your students, accept all their answers and encourage them to explain their answers. Use this discussion to get your students thinking about the concepts of size and scale and the variety of life on this planet.
In this part of the lesson, you should do a class reading of Tiny Creatures. As you read the book aloud with the class, hold up each page and let students discuss and ask questions about the pictures. In addition to doing this, you can use the guidelines below to help you go through the book with your students.
Pages 1-2: Show the picture to the students and read the text. Ask if they can find animals on the page. Are they big or small? Ask students to name some other big and small animals that they know. Ask, “Which is the biggest you can think of?” “Which is the smallest?”
Page 3. After reading the text, point to the ant. Ask, “How big would these creatures have to be that millions could fit on the ant’s antenna?”
Page 4: Read the text on the page, emphasizing that creatures that would fit on an ant’s antenna must be so small that we can’t see them with our eyes.
Pages 4-5: Read the text on this carefully. You might want to read it more than once. It introduces the word “microbes” and the number 20 million. You can take an eye dropper and show them how small a single drop of water is.
Pages 6-7: Read the next two-page spread (teaspoon of soil). You can also show the students a teaspoon of soil and compare it to the drop of water. Before going to the next page, help kids understand that these are really large numbers (this page talks about a "billion," and you may need to explain what that is) and yet we can’t see the tiny creatures so they must be very small indeed.
Page 8. This section begins the discussion of where microbes can live. Read the text on this page to the students and ask them to find some objects in the picture in which microbes can live.
Page 9. Read the text to the students. Bear in mind that if they are very young they might not have heard too much about microbes, or even if they have they might have many misconceptions.
Pages 10-11. This spread introduces the idea of microbe diversity. By showing the tiny polio virus juxtaposed with a paramecium, students should begin to see that microbes, though so small that we can’t see them, still vary a great deal in size.
Pages 12-13. This page has illustrations of microbes. Remember that these are illustrations so use this spread to help children grasp further the diversity of microbes.
Pages 14-15. This is the part of the book that begins to discuss how microbes “live” and what they “eat.” Ask students, “What are some of the things that microbes eat?” “How do they eat things?”
Pages 16-17. This is a very important concept because it lays the foundation for understanding how microbes can transform the matter that they “eat.” You can ask students, “What happens to the things that microbes eat?”
Pages 18-21. This spread introduces students to the idea of microbes “reproducing.” Ask students, “What do you think about how fast microbes can multiply?”
Pages 22-23. This spread discusses how microbes can make you sick. Davies calls them the “wrong kind” of microbe, and introduces the word “germs.” Make sure to reinforce to students that the words microbes and germs are not interchangeable and that most microbes are not harmful. Ask students, “How can germs get into your body and make you sick?”
Pages 24-25. This spread continues to reinforce the idea that most microbes are not harmful and that there are some things we can do (like washing hands) to protect ourselves from the harmful ones.
Pages 26-27. This spread introduces some of the other “jobs” microbes do, things that we wouldn’t notice them doing but that do have a large effect. Ask students, “What are some of the other things microbes do?”
Pages 28-29. This spread introduces how microbes help plants grow and keep the air breathable. This might be a good time to show the spoonful of soil again.
Pages 30-31. In this last spread, Davies reinforces the concepts from the rest of the book. A longshot of the earth from space. There are three things that microbes do: eat, multiply, change. She calls them the transformers of the world.
In order to assess student understanding, ask them to do an activity in which they draw some of their own comparisons based on the spreads in the book. Here are some examples of what students could draw:
- Big and small animals.
- Something as small as an ant’s antenna.
- Some places or things where microbes would live. (This could be anything, just so that kids could get the concept.)
- Draw one of the microbes in the book.
- Make a microbe menu.
Another idea would be to make a sheet where students can illustrate how microbes reproduce in a very simplified manner. Since microbes usually reproduce by dividing in two, students could start off with one microbe and go from there. You could provide them with a sheet that just takes them up to 16 microbes. Be sure to provide them with enough space to draw the microbes.
You can extend the ideas in this lesson by leading your students through Estimation and Measurement, another Science NetLinks lesson in which students practice measuring in an exploratory environment to develop familiarity with the concepts and tools of measurement.
To help your students to continue to develop a sense of size and scale or animals relative to one another, you can follow up this lesson by asking your students to compare Tiny Creatures with a book by Steve Jenkins called Actual Size. Ask your students to consider how both the authors and illustrators use words and pictures to help them understand size and scale. You could have your students research an animal and decide what feature of the animal they would like to illustrate. Have students use something else (another animal, an everyday household object, sports equipment) to help others understand the size and scale. (You can find this activity and several others explained on The Classroom Bookshelf site.)