## Monkeys can impress their friends with mental Math

In case it's not enough that young chimps have better numerical memory than adult humans it now seems that monkeys can perhaps impress their friends with mental Math tricks. A new study shows that monkeys can do mental Math. The article states:

"Rhesus macaque monkeys performed nearly as well as college students at quick mental addition, researchers reported Monday, adding to the evidence that non-verbal math skills are not unique to humans."

The competition involved two sets of dots that flashed briefly onto a computer screen. The humans and the monkeys had to mentally determine the sum of the two sets of dots and pick the right answer on a different screen.

The humans won this time. Whew!

## Mental Math magic by Arthur Benjamin

Check out this amazing video of Mental mathemagician Arthur Benjamin performing calculation feats in front of an audience.

The video comes from the TED.com blog. TED is an organization dedicated to changing the world by spreading important ideas. TED, which stands for "Technology, Entertainment, Design", but whose scope is much broader than when it was founded in 1984, makes their best talks and performances available for free via the Internet. These videos are made during the annual TED conferences which TED describes as follows in its about page:

The annual conference now brings together the world's most fascinating thinkers and doers, who are challenged to give the talk of their lives (in 18 minutes).

Benjamin is a Math professor at Harvey Mudd College, a college very well known for its mathematical talent among both professors and students. He is also coauthor of Secrets of Mental Math, which I've not yet read, where he apparently reveals many of his mental Math techniques.

You Tube also has a number of highly rated video clips of Benjamin.

## When you need that extra edge on the Math SAT

Do you know a high school student who's stressing over getting ready for his or her SATs, in particular the Math part? Are you wondering what to buy that special student for Christmas? Wanting a memorable gift? Want to get something he or she likely doesn't already have? Do you care enough to give the very best?

Well, look no further. Get him or her the SAT Math Concepts Shower Curtain. The product description states:

A simple, effective, and stress free learning tool for your children taking the SATs, allowing them to learn the basic SAT math concepts while taking a shower. Concepts include fractions, geometry, probability, and more!

Make every minute count!

When you purchase the SAT Math Concepts Shower Curtain through the above link you help to support this site.

## Carnival of Mathematics #22

Welcome everybody to the 22nd Carnival of Mathematics!

This edition has 16 articles and 16 is my lucky number. Very cool!

If you find these Carnivals enjoyable please spread the word and help the *blathosphere* (Math+blogosphere=blathosphere - thanks Vlorbik for this reference to the term) grow by linking to this and every Carnival and by adding Math-related blogs to your blogroll. If you're not on my blogroll and your blog has predominantly Math-related content let me know and I'll add you.

## Flexagon fun for the whole family

If you've never heard of flexagons you're in for a treat. Flexagons are flat paper constructions, some of which are really easy to make, that are tremendously fun to play with because you "flex them", hence the name, to reveal more than the two sides that you would expect to see. Some flexagons are even related to the Mobius strip.

Wikipedia has a nice article about flexagons but my very favorite flexagon site is The Flexagon Portal. The portal has a number of patterns that you can print out, preferably on a color printer, cut out, fold, then flex to your heart's content. The site has easy flexagons and others that are harder to make.

Flexagon projects are great for the kids because they can color them and create their own flexagon masterpieces. Also, they can make original flexagon Christmas cards with their own messages on them. Different parts of the greeting can be revealed on different sides of the flexagon.

While you're on the Flexagon Portal don't miss the FAQ page. There are only three FAQ items but the tips for cutting, folding and pasting are definitely worth a read. Also, check out the video on how to fold a flexagon.

You Tube has a few videos about flexagons. Here's a nice one:

## Carnival of Homeschooling #102 announced

Seeking Rest in the Ancient Paths has posted the latest Carnival of Homeschooling. Here are the Math-related articles from the Carnival:

Mandy presents __Fuzzy Math - Fuzzy Minds__ posted at __Building Blocks__.

Sol Lederman presents __What kind of Math can you do with gum drops and tooth picks?__ posted at __Wild About Math!__.

Denise takes the thinking out of Math as she presents

Math contest tip sheetsposted atLet's play math!. She has handouts on tough topics for middle school students preparing for Math Counts or other competitions, plus links to many practice problems.

## Mathcast #4: Quick squaring of 2-digit numbers

Here's a video on how to quickly square a 2-digit number. The technique is based on this algebra:

If you have a number with digits "ab" then the number is 10a+b.

(10a+b)^2 = 100a^2+20ab+b^2.

If you enjoy this video check out all of the Wild About Math! mathcasts.

## 2nd call for Carnival of Mathematics articles

I'm hosting the upcoming Carnival of Mathematics. I need submissions by Thursday night and will release the Carnival sometime Friday.

For those of you who are not familiar with blog carnivals, they're "events" in which the carnival host publishes submissions he/she deems appropriate to the theme of the carnival. This carnival is about mathematics and I'll accept pretty much any submission (blog post) related to Math. Submitting to the carnival is a nice way to get some traffic to your blog and potentially more readers. See the Carnival of Mathematics homepage for links to past carnivals for some ideas on what kinds of articles get published.

So far I've gotten submissions from Mark Dominus, Graeme Taylor, Andree, Aaron Roth, Larry Ferlazzo, Kalid Azad, and Rich Cochrane.

Please submit your blog post through the official submission form.

Thank you.

## SAGE: Open source Math software released

On December 3rd SAGE was released. Per the SAGE home page:

"Use SAGE for studying a huge range of mathematics, including algebra, calculus, elementary to very advanced number theory, cryptography, numerical computation, commutative algebra, group theory, combinatorics, graph theory, and exact linear algebra."

SAGE is a large collection of libraries (chunks of computer code written for specific tasks). It is written in the wildly popular Python scripting language. SAGE libraries can be accessed by custom Python programs and SAGE can interface to Mathematica and other popular mathematics software.

The great thing about SAGE is that it is open source, which means it's free and thus accessible to a much larger percent of the population than the commercial Math software.

To be honest, I'm not quite sure how a non-programmer would use SAGE as I have not yet downloaded the software. My sense is that there's quite of bit of work that will need to be done in terms of documentation and user interface before SAGE will be accessible to end users. I was a programmer for many years and have worked with scripting languages (of which Python is one) and I've worked extensively with Linux so I'll probably be comfortable in the bowels of the system but many people won't be. The SAGE download page provides downloads for Mac OS X, Windows using the VMware player, and Linux. There's some browser interface mechanism, through browsers plugin, I believe.

There's a slashdot discussion taking off.

I'll write more as I gain experience with SAGE. I'd love to hear from anyone who gets this running before I do.