## Wednesday, October 17, 2012

### Math: A Secret Code?

It was free day at the library book sale.  The kid went directly for the boxes on the floor at the back of the room and started searching for old books.  She's not really impressed unless it's something that is at least 100 years old.  In the past she's found some real gems, like the full-color world atlas from the 1920's, and a 125 year speller which she used to teach herself to read.  Today she hit the jackpot when she found this, from 1918:

It even had a letter hidden in its pages.  It's from one high school (maybe college) kid to another about how he made the basketball team and has finally found time to send his friend this book.  Given that we live in Indiana (you know, Hoosier basketball) that's a pretty exciting thing to find in an old book.

But the funniest thing happened when I finished celebrating her find and went back to looking for other books. She was sitting under a table, flipping through the book, and suddenly exclaimed:

"Look, Mama!  It's a secret code!"

"Cool!  Let me look..."

If you've been following this blog for a while you'll know my seven year old is basically fluent in mental sums and differences and visual math for her age, but has only experienced the symbolic realm in a cursory way.  It's been working for us so far.  Yesterday she 'discovered' a "fourthagon" in our lunch table (short video here).  And, today she was trying to convince me to top off her savings for a set of walkie-talkies.  She's got \$7.68 saved already and was imagining a set might cost around \$10.   We were out for a walk when suddenly she stopped stock still and turned inward.  Then she said,

"Mama, if you could give me \$2.33 I'd be able to buy those walkie-talkies."

"No," I said, "I think this is something you'll need to save for if you really want it."  Secretly I was completely surprised and impressed that she had figured that all out in her head within one penny.

I was tickled at her reaction to that page in the Solid Geometry book too.  Without too much giggling I said:

"You're right, that is sort of a secret code.  It's called mathematical notation.  After you understand the math concepts you'll learn the way to write them down -- it's the language of math."

I'm still giggling about the whole secret code thing -- it brings to mind a secret network of mathematical spies, or some sort of secret underground club, communicating with only the most esoteric of notation, an unbreakable code that stands for all time...[cue dramatic music].

I think she nailed it.  Out of the mouths of babes, right?  What do you think?

1. Loving it! That's a cool book. I bet it's a little dry, but you might really find some nice diagrams in there.

2. Yeah, the pictures were what drew her in. They're very cool. I've got my fingers crossed that maybe she'll make some diagrams of her own. :-)

3. Solid Geometry - we don't even teach that any more. All of my high school geometry was two-dimensional, I think. Three dimensions is so much more complex. I keep wanting to someday work my way through one of those old books.

Here's a secret code: 9-26, 25-15-21 18-15-3-11!

4. Thanks, Sue! ;-) And, she'll be thrilled to learn that it's truly 'old fashioned math'!!

5. Wonderful and what an exciting find! The story of the secret code reminded me of a book I read years ago by a Georgian educator Shalva Amonishvilli. In his book he described the first math lesson he taught to his class of 6-year olds. He writes that he first asked children whether they knew what mathematics was. A couple of children responds that it's when you can "count to 100", "add numbers", "add and subtract". He then says: "I approach a blackboard and move the curtain. On the board, in colored chalk, are Newton's identities, a formula for finding a derivative of a function, and a coordinate system with a function." Children were both amazed and excited and said that it all looked very beautiful. More importantly, they seemed to be eager to find out more about something so beautiful and mysterious.