## Tuesday, November 2, 2010

### Reflective & Rotational Symmetry & More (Geometry Class #3, Fall 2010)

Another busy day with geometry! Here's what we did:

*read "A Square Puzzle" from Mathemagic. (This book, published in 1978, as part of the Childcraft series, has many interesting stories, puzzles, and activities. You can often find it cheap!)

*shared symmetrical masks from last week, reviewed our understanding of "line of symmetry," and wrote definitions in a flap book.

*checked to see how many letters in our names are symmetrical.

*continued with lessons from Bridges, using an index card to investigate both reflective and rotational symmetry. We then explored symmetry with a variety of pattern blocks. I put a magnetic pattern block on the magnetic board, traced it, rotated, and asked the kids to stop me each time the block fit into the frame. They became very good at identifying the order of rotation and the number of lines of symmetry!

*read A Cloak for the Dreamer.

*used more Bridges lessons, building regular and irregular pentagons with toothpicks. Students followed up by drawing the shapes they made; this wasn't easy. (You try trying a regular pentagon!) We also built and drew regular and irregular hexagons.

*finished by building toothpick polygons. We'll use these next week.

Another great day! Thanks so much for all your hard work! :) If you'd like to do some "homework," check out the links below.

Great Resources for Further Study: