PiInJuly

π in July!

==[|Full recording: voice, text chat, web tour, GeoGebra, Sketchpad and spreadsheets interactives]==

Answers to two Math Future questions
Here are answers to the two questions, one we always asked before, and one we are starting.

David Chandler: Pi is the Greek letter for P. It actually stood for the perimeter. It was just a symbol that some mathematician dreamed up to stand for this famous ratio – that’s the origin of Pi, as P. If you read a sign on a billboard in Greece, you are going to see Pi’s and Sigmas and all sorts of letters we use in mathematics as extra symbols. Let me tell you a little story. I went to Harvey Mudd, which is a science and math school, and across the street was a girls’ school – excuse me, a women’s college as we say now. One of the students was sitting outside, and she had this book – she was studying Classical Greek. She said, “Boy, is this weird – I can’t read a word of this!” She showed it to me, and I started reading. I did not know the meaning of the words, but I could phoneticize it! Basically, just by doing physics and math, you end up encountering virtually every single Greek letter. You see a Pi – that’s P sound, you see a Sigma – that’s S, and you can figure out the way words are pronounced.

MariaD: This leads to a question we are going to ask everybody from now on. Can you tell us a little story about math from your childhood?

Allison Krasnow: Oh, I can tell you one thing I did not like, but then it led to a teacher, for many years, who I adored. When I was in second grade, I could do all the math that they were doing. I would get kicked out of class every day because I explained I could do everything and I wanted harder work. My teacher had nothing for me to do, and she made me memorize my times tables all the way through 25s. And every day, I would have to come in and tell her the 13s, and the next day the 14s… It was an example of the worst thing you can do to a bright young girl interested in math. Consequently, I finally ended up in a right place for math classes, with a teacher I fell in love is, whom I had for four years. I was really inspired by a teacher who was so excited about math that he taught, and that led me to where I am today.

MariaD: What would you tell your teacher now, if you met – the one who made you memorize times tables to 25s?

Allison Krasnow (laughs): I think I would invite her to one of my classes!

MariaD: Here is the second question we always ask. How can people help you in what you do and collaborate with you?

Allison Krasnow: I met David originally online, and later in person. For me, it’s being a part of professional networks. I am currently at a three-week math institute, where I am meeting the most inspiring teachers from all over the country, and learning so much. It’s staying connected to like-minded people who can really inspire you, help you learn more math, and also become better at your own teaching. I met David through a common interest – “Escape from the Textbook” network – and then we met at this conference in person. (Math Future event with Henri Picciotto, the founder of “Escape from the Textbook” – MD.) He is eager to share his ideas with me, and I sort of took them and ran with them in my own direction, integrating them with GeoGebra which is my own personal interest. So, for me, it’s about staying connected with people who inspire you.

David Chandler: I am doing a lot of things on my own, but I learn by interacting. I only discovered GeoGebra a few months ago. I became pretty fluent at it, but there is lots more… I should not even say “fluent” because I know there is a lot of depth to it I have not even touched yet. I am really interested in various kinds of tools. I have done Algebra I and Algebra II – some people here are aware of that. I have actually recorded an entire school year and I have it out on DVDs. (David’s home study sets are at [|Math Without Borders] – MD.) I am working on Pre-Calculus and one of the things I am doing is integrating various kinds of technology in the process. I am using GeoGebra, Geometer’s Sketchpad, spreadsheets and probably several others – Open Source Physics I really like, and use for math, too. You can take a video and put a number on any frame, so you can toss a ball and study the projectile motion and so forth. All these wonderful tools give you access to the real world at much more depth than you can have with a hand-held calculator and pencil and paper. So, if anybody has things like that to share, I am really keen on learning them! (transcribed by Maria Droujkova)

About Pi in July
π is a mystery to students when it is first introduced. (For many it remains a dreaded mystery.) It is typically the first irrational number encountered in the school curriculum. It is a number you can't really write down...only approximate. It is represented with an unfamiliar Greek letter, adding more mystery than clarity.

π is 3.14, but not really. π is 22/7, but not really. You can memorize it to 50 places or more, but it's still not really π. (Where do all those digits come from, anyway? Who can measure that accurately?) Yet π has a simple and exact definition. Archimedes used the definition and an ingenious "iterative" method (a method based on successive approximations) to derive the value of π without using measurement, and thus without the limited precision of measuring instruments.

During this event, David Chandler will introduce the meaning of π, the "magic number for circles", as he does in his classes. Then, following in the footsteps of Archimedes, he will show us how we can calculate π for ourselves, to as many digits of precision as our calculating devices will allow. (Once you can find the number for yourself, it's yours.) We will use a spreadsheet. Remember, Archimedes did it all by hand, and he didn't even have decimal fractions to work with!

The only prerequisite knowledge to be able to follow the derivation is the Pythagorean Theorem. Since this presentation is open to the world and a mixed group of teachers, homeschooling parents, and students are being invited, here is a brief introduction to the Pythagorean Theorem: how to use it, and several very graphic ways it can be proved.

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**How to join**

 * Thursday, July 7 we will meet in the LearnCentral online room at 6:00pm Pacific, 9:00pm Eastern time. [|WorldClock for your time zone.]
 * Follow this link at the time of the event: **[|http://tinyurl.com/math20event]**
 * Click "OK" and "Accept" several times as your browser installs the software. When you see Elluminate Session Log-In, enter your name and click the "Login" button
 * If this is your first time, come a few minutes earlier to check out the technology. The room opens half an hour before the event.

All events in the Math 2.0 weekly series: http://mathfuture.wikispaces.com/events

Recording and questions
The recording will be at http://mathfuture.wikispaces.com/PiInJuly Prepare your questions at [] and the moderator will ask them during the event. rss url="http://ask.mathseeker.com/feed/62/comments-and-answers.rss" link="true" description="true" length="400" number="10" date="true" author="true"

Event Hosts

 * **[[image:DavidChandler.jpg align="left"]]David Chandler** writes:

I currently teach at Eleanor Roosevelt Community Learning Center, a California public charter school that supports homeschooling families. I have addressed the issue of homeschooling parents trying to teach high school math by recording the entire Alg I and Alg II courses (following the classic Foerster textbooks and using a screen capture video process), and also created a set of supplementary materials for the wonderful text, //Geometry: A Guided Inquiry// (by Chakarian, Crabill, and Stein) built largely around The Geometer's Sketchpad. See my website, [|http://www.mathwithoutborders.com] for samples of the videos and course descriptions. ||
 * [[image:AllisonKrasnow.jpg align="left"]]**Allison Krasnow** writes:

I currently teach Pre-Algebra, Algebra 1 and Geometry at Willard Middle School in Berkeley, CA. Over the past 12 years I have taught math from 4th grade through geometry and spent many of those years as a Spanish bilingual teacher. My current classroom interests are on developing Algebra 1 and Geometry curriuculum using GeoGebra. ||