Subject Area: 
Mathematics 
Strand: 
Shape and Space

Grade Level: 
Four

Content (topic) 
Understanding Symmetry through Nature

WNCP: 
Outcome SS4.4: 
Demonstrate an understanding of line symmetry by:
 Identifying symmetrical 2D shapes
 Creating symmetrical 2D shapes
 Drawing one or more lines of symmetry in a 2D shape.

Indicators: 
 Determine whether or not a given 2D shapes and explain why each shape is symmetrical.
 Provide examples of symmetrical shapes found in the environment and identify the lines of symmetry.
 Sort a given set of 2D shapes as those that have no lines of symmetry, one line of symmetry, or more than one line of symmetry.

Mathematical Processes: 
Connections
Mental Mathematics
Visualization


Lesson Preparation

Equipment/materials:
 Rosella Carney video titled “Birch Bark Biting”.
 Copies of the “Examples of Birch Bark Biting” for every student
Advanced Preparation:
 Read the background information on Birch Bark Biting.
 Have the video ready for student
 Print sufficient copies of the “Examples of Birch Bark Biting” for the students.
 Have an example of symmetry found outdoors (e.g., the ladder attached to the play structure).
 If possible, bring in some examples from nature that illustrate symmetry, such as grass or leaves.

Presentation 
Set
 Play the video titled “Birch Bark Biting with Rosella Carney” and have the students look for examples of symmetry throughout the video.
 Play the video titled “Birch Bark Biting with Rosella Carney” and have the students look for examples of symmetry throughout the video.
 After the video, ask the students to determine whether or not the picture of birch bark biting is symmetrical and to circle three example of symmetry along with orally explaining why those are symmetrical.
Development
 Next, ask students whether or not they are able to think of examples in nature that are symmetrical (e.g., tree leaves, faces of animals and people, grass, butterflies, flowers, etc.).
 Hand out the images of birch bark biting in which is found in “Examples of Birch Bark Biting.” Have students draw lines across their paper that demonstrates the lines of symmetry.
 Take students outside into the schoolyard and assemble them into groups of three. Ask the students to find three different objects, which are symmetrical, and to draw these objects in their math journals with a broken line to indicate the lines of symmetry.
 Have the students draw a 2D object which has no lines of symmetry, one line of symmetry, and more than one line of symmetry.
