Wild About Math! Making Math fun and accessible

Seeking interesting math factoids about the number 11

I'll be doing a brief talk at a conference next month, on 11/11/11 at 11:11AM, about the number 11. If you know interesting factoids about 11 (or about 1111...) that I could include in the talk I'd greatly appreciate it.

One factoid is that 1/(1+(1/(1+1/(1+... converges to the golden ratio.

Another is that if a number is divisible by 11, reversing its digits will result in another multiple of 11.

Other ideas?

Thanks.

A practical math test

From xkcd.

Hat tip to Jon McLoone.

Stephen Wolfram on Steve Jobs and his influence on Mathematica

Stephen Wolfram wrote a nice article on his personal blog: Steve Jobs: A Few Memories.

Real-world math activities at yummymath.com

[ Editor's note: Brian at Yummymath contacted me on twitter to introduce me to his web-site. I hadn't heard about it so I went to check it out. I liked what I saw and I offered to promote the site if he wrote a guest article. Here's the guest article. ]

Making Math Meaningful to Students: www.yummymath.com

Have you ever heard math students ask “Why do we need to learn this?” or “When am I ever going to use this?” There is a relatively new website, www.yummymath.com whose purpose is to help educators answer those exact questions. The website provides authentic and timely math activities that relate to real life happenings. Math activities are written
about current events that are of interest to students, including sports, technology, movies,
big news stories and holidays. While the activities are written about topics that kids can
relate to, the activities focus on number sense reasoning, problem solving and conceptual
development of math concepts.

Yummymath activities incorporate real life data. For example, a recent activity was
written about the NFL to coincide with the start of the NFL season. The activity was
centered on actual NFL team values, something that is relevant to many students. The
activity represented actual NFL franchise values in bar graph form and focused on
visualizing the concept of the mean. Other notable recent activities include an analysis of
the Harry Potter movie franchise, which coincided with the final Harry Potter movie, and
a “hurricane math” activity that coincided with Hurricane Irene.

Two new videos by James Tanton

After a hiatus of several months Dr. Tanton is making videos again. Here are two new ones.

Lulu has two children. You are told that at least one of her children is a boy who was born on a Tuesday. What is the probability that her other child is also a boy?

The answer will surprise you!

Here is a cute geometry puzzle: Imagine you are an archeologist and have come across just a small section of a rim of an ancient wheel. What size wheel did it come from?

This is a great puzzle to give to geometry students too. Hand out a picture of an arc of a circle and ask if is possible to find the measure of that arc using only basic tools - and them have students actually do it.

An infinite number of mathematicians walk into a bar …

From Instapundit

Math joke from Anna, the bartender and civil engineering student: an infinite number of mathematicians walk into a bar. The first one tells the bartender he wants a beer. The second one says he wants half a beer. The third one says he wants a fourth of a beer. The bartender puts two beers on the bar and says “You guys need to learn your limits.”

Hat tip to Algut Runeman at MathFuture.

Paper-folding proof of Pythagoras

Here's a great video by Vi Hart that shows a couple of proofs of the Pythagorean Theorem. Nothing new in terms of the proofs; they're ones I've seen often. What's clever about Vi's approach is that she uses paper-folding to create the elements of the proof. I like this kinesthetic approach to a couple of familiar proofs.

As always with Vi's exuberant videos, it would be nice to be able to watch them at half speed!

Enjoy!