Monthly Archives: December 2012

Mayans, Calendars, and Ramanujan

Welcome to this week’s Math Munch!

There’s been a lot of fuss recently about the Mayan calendar and the “end of the world.” You’ll be relieved to hear that the world continues to hang in there. In fact, no less an authority than NASA put out a video to help clear up the misinformation surrounding the rolling over of the Mayan calendar.

mayanAll of the doomsday talk did get me researching the Mayan calendar and number system. Check out this page that discusses Mayan numerals and will even count and skip-count for you. Once you’ve got the knack of how to count in the Mayan system, maybe you’ll want to try to decipher the numbers on a Mayan ballcourt marker in this interactive applet.

A cool fact that I learned from that first page is that the Mayans also had another and fancier way of writing down numbers: face glyphs. I found a really comprehensive article by Mark Pitts that describes both face glyphs and the ordinary system, too.


The Mayan face glyphs for 0, 1, 2, and 3:
mih, jun, cha’, and ux.

There are many interesting kinds of calendars that human being have developed over the centuries, all with different styles, different mathematical patterns, and different connections to the natural and human worlds. We’ve featured the Cloctal before, but how about some links to some other fun mathy calendars as the new year approaches?


Thursday, January 1—in pennies.

I’m always amazed by what the internet produces when I dream up a search term like “binary calendar.” Perhaps you’ve seen a binary clock before—if not, check out this one—but I was delighted to find several different takes on a binary calendar served up by Google. Juan Osborne designed a binary calendar with all of the dates written out it a big colorful loop. Next, can you figure out the secret to this wooden binary calendar by Ken and Bobbie Ralphs? (It’s a lot like a marble calculator.) And third, here’s a binary calendar that you can make using just twelve pennies, courtesy of!


The Aztec tonalpohualli calendar.

There are many more amazing calendars to explore. Maybe you’ll check out Aztec calendar wheels, or find out about anniversaries of mathematicians from this calendar. (Isaac Newton was born on Christmas!) There are even more great calendars to explore at the Calendar Wiki, including some new calendars that have been proposed to “fix” our calendar—the Gregorian calendar—to get rid of traits like uneven months and leap years.

RamanujanSpeaking of anniversaries, this past Saturday was the 125th anniversary of the birth of the great Indian mathematician Srinivasa Ramanujan. Google celebrated the occasion with this doodle on the Indian Google homepage.


Ramanujan’s story is inspiring and also in some ways tragic. There’s plenty of information about Ramanujan on the web, but you might particularly enjoy reading this recent tribute to him by Dilip D’Souza. One surprising fact I ran across is that one of Ramanujan’s formulas involving pi appeared in (of all places) the movie High School Musical.


One of Ramanujan’s infinite series, which made an appearance in High School Musical.

Ramanujan’s 125th birthday this year became the occasion for India’s first National Mathematics Day. What a cool holiday! Here is a clip from Indian television that shows some Indian students honoring Ramanujan and doing some math.

I can’t understand everything that’s happening in the video, but it’s simply amazing to catch a glimpse of students on the other side of the world being excited about math. Also, you might notice that some of the students are figuring out cube roots of large numbers, while some others are shown figuring out what day of the week certain dates fell on. That’s a neat calendar-related feat that you can read more about here.

And just because it made me giggle, here’s a little bonus video.

Bon appetit!

The Museum of Math, Shapes That Roll, and Mime-matics

Welcome to this week’s Math Munch!  We have so many exciting things to share with you this week – so let’s get started!

Something very exciting to math lovers all over the world happened on Saturday.  The Museum of Mathematics opened its doors to the public!

MoMath entranceThe Museum of Mathematics (affectionately called MoMath – and that’s certainly what you’ll get if you go there) is in the Math Munch team’s hometown, New York City.

human treeThere are so many awesome exhibits that I hardly know where to start.  But if you go, be sure to check out one of my favorite exhibits, Twist ‘n Roll.  In this exhibit, you roll some very interestingly shaped objects along a slanted table – and investigate the twisty paths that they take.  And you can’t leave without seeing the Human Tree, where you turn yourself into a fractal tree.

coaster rollersOr going for a ride on Coaster Rollers, one of the most surprising exhibits of all.  In this exhibit, you ride in a cart over a track covered with shapes that MoMath calls “acorns.”  The “acorns” aren’t spheres – and yet your ride over them is completely smooth!  That’s because these acorns, like spheres, are surfaces of constant width.  That means that if you pick two points on opposite ends of the acorn – with “opposite” meaning points that you could hold between your hands while your hands are parallel to each other – the distance between those points is the same regardless of the points you choose.  See some surfaces of constant width in action in this video:

Rouleaux_triangle_AnimationOne such surface of constant width is the shape swept out by rotating a shape called a Reuleaux triangle about one of its axes of symmetry.  Much as an acorn is similar to a sphere, a Reuleaux triangle is similar to a circle.  It has constant diameter, and therefore rolls nicely inside of a square.  The cart that you ride in on Coaster Rollers has the shape of a Reuleaux triangle – so you can spin around as you coast over the rollers!

Maybe you don’t live in New York, so you won’t be able to visit the museum anytime soon.  Or maybe you want a little sneak-peek of what you’ll see when you get there.  In any case, watch this video made by mathematician, artist, and video-maker George Hart on his first visit to the museum.  George also worked on planning and designing the exhibits in the museum.

We got the chance to interview Emily Vanderpol, the Outreach Exhibits coordinator for MoMath, and Melissa Budinic, the Assistant Exhibit Designer for MoMath.  As Cindy Lawrence, the Associate Director for MoMath says, “MoMath would not be open today if it were not for the efforts” of Emily and Melissa.  Check out Melissa and Emily‘s interviews to read about their favorite exhibits, how they use math in their jobs for MoMath, and what they’re most excited about now that the museum is open!

mimematicsLogo (1)Finally, meet Tim and Tanya Chartier.  Tim is a math professor at Davidson College in North Carolina, and Tanya is a language and literacy educator.  Even better, Tim and Tanya have combined their passion for math and teaching with their love of mime to create the art of Mime-matics!  Tim and Tanya have developed a mime show in which they mime about some important concepts in mathematics.  Tim says about their mime-matics, “Mime and math are a natural combination.  Many mathematical ideas fold into the arts like shape and space.  Further, other ideas in math are abstract themselves.  Mime visualizes the invisible world of math which is why I think math professor can sit next to a child and both get excited!”

One of my favorite skits, in which the mime really does help you to visualize the invisible world of math, is the Infinite Rope.  Check it out:

slinkyIn another of my favorite skits, Tanya interacts with a giant tube that twists itself in interesting topological ways.  Watch these videos and maybe you’ll see, as Tanya says, how a short time “of positive experiences with math, playing with abstract concepts, or seeing real live application of math in our world (like Google, soccer, music, NASCAR, or the movies)  can change the attitude of an audience member who previously identified him/herself as a “math-hater.””  You can also check out Tim’s blog, Math Movement.

Tim and Tanya kindly answered some questions we asked them about their mime-matics.  Check out their interview by following this link, or visit the Q&A page.

Bon appetit!

Math Comics, A+ Click, and a Mathematical Advent Calendar

Welcome to this week’s Math Munch!

Ada Lovelace | the first computer scientist

Ada Lovelace | the first computer scientist

Up first, are you enjoying the technology you’re reading this on? Well you can thank Ada Lovelace for that. She’s the 19th century mathematician that worked on the first computing machines with Charles Babbage and is often called “the first computer scientist.” There’s no better day to thank her than today, since it’s Ada’s 197th birthday. Justin found a great little comic dramatizing her life and work. It’s called “2D Goggles or The Thrilling Adventures of Lovelace and Babbage.” It’s also available as a free iPad app called Lovelace & Babbage, in case you have one of those.

Ada Lovelace | The first computer scientist

Ada Lovelace hard at work in comic book form

Bertrand Russell from Logicomix

Bertrand Russell from Logicomix

I can also recommend one other math comic. It’s a graphic novel called Logicomix: An Epic Search for Truth detailing the life and research of English logician Bertrand Russell, a personal hero of mine. You can buy it here.

A+ ClickUp next, I found a nice little web resource lately called A+ Click. It’s basically just a collection of math tests, but they have them for every level, and the problems are actually pretty great. Give it a try, and don’t feel like you have to stick to your grade. There’s bound to be tough ones and easier ones in every set. You can actually learn a lot by working on new kinds of problems you’ve never even heard of. You just have to figure out what the words mean, so here’s an illustrated mathematical glossary to help you out, or this maths dictionary for kids.  And here’s a sample problem I like:

Add the adjacent numbers together and write their sum in the block above them. What is the number at the top of the pyramid?

Add the adjacent numbers together and write their sum in the block above them. What is the number at the top of the pyramid?

I wonder if there was a way to predict the answer without filling in all the boxes. And what if the pyramid had 1,2,3,4,5,… all the way up to 10? Hmmmm. Any readers have any ideas? Just leave us a comment.

+plus magazineFinally, Plus Magazine’s website is full of really good math articles and things. For the holiday season, they’ve created a mathematical advent calendar. Each day, a new “door” can be opened which leads to further links and descriptions to neat math content. For example, on the 8th day we had Door #8: Women in Maths, including information about Ada Lovelace!

And here’s a little bonus video for you this week. For their recent music video, Lost Lander decided to illustrate the prime numbers as they build up. It’s quite nice, and not a bad song either.

Bon appetit!

Mathpuzzle, Video Contests, and Snowflakes

Welcome to this week’s Math Munch!


One of my favorite math sites on the internet is mathpuzzle. It’s written and curated by recreational mathematician Ed Pegg Jr. About once a month, Ed makes a post that shares a ton of awesome math—interesting tilings, tricky puzzles, results about polyhedra and polyominos, and so much more. Below are some of my favorite finds at mathpuzzles. Go to the site to discover much more to explore!


Shapes that three kinds of polyominoes can tile.


Erich Friedman’s 2012 holiday puzzles


A slideable, flexible hypercube you can hold in your hands! Video below.


Next, have you ever wanted to be a movie star? How about a math movie star? Then there are two math video contests that you should know about. The first is for middle schoolers— the Reel Math Challenge. It’s run by MATHCOUNTS, which has for many years run a middle school problem solving contest. (I competed in it when I was in middle school.) This is only the second year for the Reel Math Challenge, but lots of videos have already been created. You can check them out here.

MathovisionThe second contest is for high schoolers and is called Math-O-Vision. The challenge is to make a video that shows “the way Math fills our world.” Math-O-Vision is sponsored by the Dartmouth College Math Department and the Neukom Institute.

makeaflakeFinally, here’s a fun little applet I found called Make-a-Flake. You can use it to make intricate digital snowflake designs.


Two snowflakes from the Make-a-Flake gallery.

Of course, it’s a lot of fun to make non-virtual snowflakes as well—find a pair of scissor and some paper and go for it! For basic instructions, head over to And for some inspiration, check out this Flickr group!

Bon appetit!