Primary Math Activities
Intro to Geometry
Describe the Shape
Describe the Shape
Objective: to show rotational symmetry using pattern blocks.
Manipulative Activity: Explain to the students that an object that looks the same no matter how you turn it has rotational symmetry. Give examples of objects that have rotational symmetry.
To demonstrate, take three triangles and put a dot within the same angle on each triangle. Ask a student to "rotate" the second triangle so that the dot has moved, but the triangle looks the same. Ask another student to "rotate" the third triangle so that the dot is not in the same position as in either the first or second triangle, but the triangle looks the same.
Continue this demonstration with squares (How many different squares do you need?), hexagons, trapezoids, and rhombuses. Do all of these shapes have rotational symmetry?
Technology Activity: Students will use a pattern block applet written by Jacobo Bulaevsky to reinforce the idea of rotational symmetry. Point out the rotation tool for the applet.
Have students go to Rotational Symmetry.
Paper/Pencil Activity: Depending on the level of your students, you can have them complete this activity individually or with assistance. Here are some possible activities:
- Students use pattern blocks to create rotational symmetry.
- Print this triangle grid paper to color in the designs.
- Students define rotational symmetry.
- Students write about things in the environment that have rotational symmetry.
- Students use magazines to cut out pictures and make a book about
things that have rotational symmetry.
Let's Fly A Kite
Stuart J. Murphy, (Harpercollins Juvenile Books, September 30, 2000)
© 1994- The Math Forum at NCTM. All rights reserved.
Home || The Math Library || Quick Reference || Search || Help
Send comments to: Varnelle Moore