Rimwe Educational Resources 

Summer is here and that means lots of opportunities for outside fun and learning!  Today's blog contains a sample activity of the Summer STEM Series that Rimwe offers. [Note:  We create custom curriculum and educational materials!  Contact us for more information!]

Venn Diagrams & Turtle Classification

Overview: An animal commonly seen in your backyard is a turtle.  Today we are going to learn some fun turtle facts and a cool way to classify turtles using a special kind of diagram.

Goals:  This exploration has two main goals:  (1) Learn some fun facts about turtles.  (2) Learn how to use a Venn Diagram to classify turtles.

Materials Needed:  You can do this exploration with very simple and easy-to-find materials.  You will need several copies of the Venn Diagram template, many pictures of turtles (color printed copies of the Google image search are great for this), scissors, glue, markers, and some good reference books (or websites) to look up information about different kinds of turtles (a partial reference list is given at the end of this activity).

Description of Activity:  Begin by asking how many of the participants have seen a turtle (or maybe even had one as a pet).  Continue the conversation by asking them to tell you what they know about turtles.  If you have enough reference materials (or internet access), give the participants about 10 minutes to look up interesting information about turtles to share with the group.  As a whole group, create a list of “fun facts” about turtles.  Possible items may include:

1. Turtles are the only reptiles with no teeth!
2. Don’t be fooled though, many turtles still bite (and it can hurt A LOT!).
3. Turtles are the only reptiles that have a shell.
4. Turtles are the oldest-living reptile group (they have been around for 200,000,000 years!).
5. Turtles are among the longest living of all animal groups (up to 150 years!)
6. There are types of turtles that live on land, and in fresh water, and in salt water.
7. Some turtles weigh less than one pound (like the American Freshwater Turtle) and others weigh over 1,500 pounds (like the Leatherback Turtle)!
8. Since turtles are cold-blooded, they can’t live in places that are cold all year long (like the arctic), but they live almost everywhere else (in deserts, in forests, in mountains, in swamps, in rivers, in the ocean, in grasslands, etc.).
9. The shell of a turtle is composed of a mix of bone and horn.  It is like a suit of armor and offers great protection against predators.
10. Many turtles are in danger of extinction due to lack of habitat.

Any one of the above turtle facts may lead to a further discussion about how to “classify” or organize the different kinds of turtles.  Classification, that is, sorting things into categories to show what is the same and what is different, is one of the primary tools scientists use to describe our world.  Sometimes it is difficult to explain to someone else the method used in sorting – this is a problem that was solved by math!  Share with the group the following information about John Venn and his classification method:

In the late 1800’s (around 133 years ago), a British man named John Venn came up with a way to illustrate (draw) the relationship between groups of items.  In math, groups of similar items are called sets.  For example, we may create two different sets of people in this room: one of adults and one of children, or one of boys and one of girls.  Venn’s method, called a Venn Diagram, is very simple to use:  a rectangular box is drawn to represent the “universe” (that is, the big set that is being discussed – for example, our universe might consist of all reptiles), then circles are drawn to represent various sets of elements within that universe (in our example, we may have a circle that represents turtles).  [On the board, make a copy of the drawing shown below:]

Now, at this point you may be thinking, “Wow, this guy John got credit for this idea?  It doesn’t seem that big a deal to me.” Well, you’re right:  in a way, it is a really simple idea; that’s partly why it is so useful.  However, John Venn went a bit further with his diagram, showing, with circles representing different sets, the relationships between them. If the circles do not touch (overlap), then it means that the sets have no element in common.  Sets that do not have any elements in common are called disjoint sets.  For example, if we used our class as the universe, the Venn diagram might look like this because no one is both a boy and a girl (there are no elements in common): [Make a copy of this on the board as well.]

If there ARE elements in common between two sets, then the circles are drawn overlapping each other and the common area is called the “intersection”.  Sets that share one or more elements are called intersecting sets.  For example, if we used “animals” as the universe then there would be elements in common (turtles!) between the set of all reptiles and the set of all animals with a shell: [Draw this diagram on the board as well.] 

Ask participants to think of characteristics that could be used in classifying turtles, along with the sets we would need to sort the turtles into.  Small groups can be formed according to interest:  for example, one group might use habitat as the classification system and sort the turtles into sets of “mostly land” and “mostly water’. 

Working in their small groups, participants will create a Venn Diagram to illustrate how they have sorted the various types of turtles. Groups can then exchange diagrams and have discussions to learn more about how others sorted the turtles.  

Summer is the perfect time to take learning outside, make it more connected to the world (or backyard), and help students see that learning happens year-round, not just in school!  As always, I'd love to hear from you.

References:

Turtle images from Google: link

Turtles & Turtle Care: http://www.turtles.net/

Turtle Information: http://animal.discovery.com/reptiles/turtle-info.htm

Venn Diagram Templates: http://timvandevall.com/printable-venn-diagram-template/

Behler, J. L., & King, F. W. (1979). National Audubon Society Field-Guide to North American Reptiles & Amphibians. New York, NY: Chanticleer Press, Inc.

The Solver Blog

Author:  Dr. Diana S. Perdue