During this project, students use rubber bands to enlarge photographs of butterflies available at the Butterflies of Illinois website.

Procedure:

Tie a knot in the middle of a rubber band. Securely anchor one end of the rubber band (at Point P) to form an anchor point. Place a pencil through the other end of the rubber band and position the knot above a part of the figure. Move the knot over the various parts of the figure using the pencil to trace the enlargement.

NOTE: This is not a truly accurate method of enlarging figures. Student should discover that the picture is doubled, or enlarged by a scale factor of 2.

Challenge students to experiment with this method by placing the knot at various points along the rubber band - closer to or further away from the anchor point.