This week's math class continued with symmetry...
We read
Snowflake Bentley
, a Caldecott winning book, that tells the true story of Wilson Bentley, who first captured individual snowflakes on film. We noted that Willie was homeschooled until age 14.
Some speculate that Bentley may have been autistic.
Bentley said, "I found that snowflakes were masterpieces of design. No one design was ever repeated. When a snowflake melted...just that much beauty was gone, without leaving any record behind."
Two years ago my husband and I were in Vermont. Driving through Jericho, I noticed a snowflake sign on the "Old Red Mill." We inadvertently discovered the
Snowflake Bentley Exhibit with a tiny museum housing Bentley's cameras as well as some of his photos. If you're ever in Jericho, Vermont, be sure to visit! (pictured, left)
Using
Bridges materials, my students made their own snowflakes using paper pattern blocks.
After thinking about the meaning of "line of symmetry," we sorted our snowflakes. It took a lot of work to figure out how many lines of symmetry in each! We held a ruler in front of each image so we could imagine where the line(s) might be. One snowflake had rotational symmetry; we will explore that in more depth next week.
As a last, optional, activity, students could make a symmetrical mask. I saw this posted on
Mathwire and wanted to use it as an extension of our lesson on "line of symmetry."
If you'd like, try some symmetry activities on-line:
Symmetry Game
Learn About Symmetry
Symmetry Pattern
Cyberchase Symmetry
Symmetry Shape Games
Finish the Symmetry Picture
List of Kids' Symmetry Links
Also, check out this
snowflake set
. What a fun way to explore tessellations!
and Magic Mirror Tricks
show incomplete illustrations--sometimes halves of objects, especially in the tricks book, hence the link to symmetry--that children can complete by holding a small mirror up next to the picture. The books, though out-of-print, can be found very cheaply.
to complete the puzzle. 
, Patternables
and Magnetic Pattern Blocks
. (That last one should have given me a clue!) I took all the pages out of the first two books, slipped each page into a plastic sleeve, and put them all into a 3-ring binder. This allows multiple children to use materials at once; I just pull out a page or two at a time.
At first, I gave my newly 5yo some cutouts and helped him with the symmetry. In time, however, I faced up to the inevitable. He was having entirely too much fun with DECORATING and could have cared less about the symmetry involved. That's okay. We're all about fun here, too! :)
. My older kids memorized this poem when they were little. Now I'm working on it with my younger two. The book itself is gorgeous and one that we pull out and read several times each winter.
and tell them to begin with a relatively flat structure...more picture-like than building-like.
. (This book, published in 1978, as part of the Childcraft series, has many interesting stories, puzzles, and activities. You can often find it cheap!)
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!
. 
