Grab your M&Ms and ace math this year with Math Bytes

In this segment from WCCB in Charlotte, NC, Tim Chartier shows how math can be both educational and delicious! This experiment is taken directly from his recent book Math Bytes: Google Bombs, Chocolate-Covered Pi, and Other Cool Bits in Computing. There are lots of other hands-on experiments that are suitable for aspirational mathematicians of all ages in the book.


bookjacket Math Bytes:
Google Bombs, Chocolate-Covered Pi, and Other Cool Bits in Computing
Tim Chartier

Quick Questions for Tim Chartier, author of Math Bytes

Tim Chartier, Photo  courtesy Davidson CollegeTim Chartier is author of Math Bytes: Google Bombs, Chocolate-Covered Pi, and Other Cool Bits in Computing. He agreed to be our first victi… interview subject in what will become a regular series. We will ask our authors to answer a series of questions in hopes to uncover details about why they wrote their book, what they do in their day job, and what their writing process is. We hope you enjoy getting to know Tim!

PUP: Why did you write this book?

Tim Chartier: My hope is that readers simply delight in the book.  A friend told me the book is full of small mathematical treasures.  I have had folks who don’t like math say they want to read it.  For me, it is like extending my Davidson College classroom.  Come and let’s talk math together.  What might we discover and enjoy?  Don’t like math?  Maybe it is simply you haven’t taken a byte of a mathematical delight that fits your palate!

PUP: Who do you see as the audience for this book?

TC: I wanted this book, at least large segments of it, to read down to middle school.  I worked with public school teachers on many of the ideas in this book.  They adapted the ideas to their classrooms.  And yet, the other day, I was almost late taking my kids to school as I had to pull them from reading my book, a most satisfying reason.  In my mime training, Marcel Marceau often said, “Create your piece and let the genius of the audience teach you what you created.”  I see this book that way.  I wrote a book that I see my students and the many to whom I speak in broad public settings smiling at as they listen.  Who all will be in the audience of this book?  That’s for me to learn from the readers.  I look forward to it.


Don’t like math? Maybe it is simply you haven’t taken a byte of a mathematical delight that fits your palate!


PUP: What do you think is the book’s most important contribution?

TC: When I describe the book to people, many respond with surprise or even better a comment like, “I wish I had a teacher like you.”  My current and former students often note that the book is very much like class.  Let’s create and play with ideas and discover how far they can go and, of great interest to me, how fun and whimsical they can be.

PUP: What inspired you to get into your field?

TC: My journey into math came via my endeavors in performing arts.  I was performing in mime and puppetry at international levels in college.  Math was my “back-up” plan.  Originally, I was taking math classes as required courses in my studies in computer science.  I enjoyed the courses but tended to be fonder of ideas in computer science.  I like the creative edge to writing programming.  We don’t all program in the same way and I enjoyed the elegance of solutions that could be found.  This same idea attracted me to math — when I took mathematical proofs.  I remember studying infinity – a topic far from being entirely encompassed by my finite mind.  Yet, through a mathematical lens, I could examine the topic and prove aspects of it.  Much like when I studied mime with Marcel Marceau, the artistry and creativity of mathematical study is what drew me to the field and kept me hooked through doctoral studies.

PUP: What is the biggest misunderstanding people have about what you do?

TC: Many think mathematics is about numbers.  Much of mathematics is about ideas and concepts.  My work lies at the boundary of computer science and mathematics.  So, my work often models the real world so often mathematics is more about thinking how to use it to glean interesting or new information about our dynamic world.  Numbers are interesting and wonderful but so is taking a handful of M&Ms and creating a math-based mosaic of my son or sitting with my daughter and using chocolate chips to estimate the value of Pi.  And, just for the record, the ideas would be interesting even without the use of chocolate but that doesn’t hurt!

PUP: What would you have been if not a mathematician?

TC: Many people think I would have been a full-time performer.  I actually intentionally walked away from that field.  I want to be home, have a home, walk through a neighborhood where I know my neighbors.  To me, I would have found a field, of some kind, where I could teach.  Then, again, I always wanted to be a creative member of the Muppet team – either creating ideas or performing!


I pick projects that I believe aren’t just exciting now, but will be exciting in retrospect.


PUP: What was the best piece of advice you ever received?

TC: At one time, I was quite ill.  It was a scary time with many unknowns.  I remember resting in a dark room and wondering if I could improve and get better.  I reflected on my life and felt good about where I was, even if I was heading into my final stretch.  I remember promising myself that if I ever got better that I would live a life that later — whether it be a decade later or decades and decades later — that I would try to live a life that I could again feel good about whenever I might again be in such a state.  I did improve but I pick projects that I believe aren’t just exciting now, but will be exciting in retrospect.  This book is easily an example of such a decision.

PUP: Describe your writing process. How long did it take you to finish your book? Where do you write?

TC: The early core of the book happened at 2 points.  First, I was on sabbatical from Davidson College working at the University of Washington where I taught Mathematical Modeling.  Some of the ideas of the book drew from my teaching at Davidson and were integrated into that course taught in Seattle.  At the end of the term, my wife Tanya said, “You can see your students and hear them responding.  Sit now and write a draft. Write quickly and let it flow.  Talk to them and get the class to smile.”  It was great advice to me.  The second stage came with my first reader, my sister Melody.  She is not a math lover and is a critical reader of any manuscript. She has a good eye.  I asked her to be my first reader.  She was stunned.  I wanted her to read it as I knew if she enjoyed it, even though there would be parts she wouldn’t understand fully, then I had a draft of the book I wanted to write.  She loved it and soon after I dove into the second draft.

PUP: Do you have advice for other authors?

TC: My main advice came from award-winning author Alan Michael Parker from Davidson College.  As I was finishing, what at the time I saw as close to my final draft, Alan said, “Tim, you are the one who will live with this book for a lifetime.  Many will read it only once.  You have it for the rest of your life.  Write your book. Make sure it is your voice.  Take your time and know it is you.”  His words echoed in me for months.  I put the book down for several months and then did a revision in which I saw my reflection in the book’s pages — I had seen my reflection before but never as clearly.


Tim is the author of:

bookjacket

Math Bytes
Google Bombs, Chocolate-Covered Pi, and Other Cool Bits in Computing
Tim Chartier

“A magnificent and curious romp through a wonderful array of mathematical topics and applications: maze creation, Google’s PageRank algorithm, doodling, the traveling salesman problem, math on The Simpsons, Fermat’s Last Theorem, viral tweets, fractals, and so much more. Buy this book and feed your brain.”–Clifford A. Pickover, author of The Math Book

Math Bytes is a playful and inviting collection of interesting mathematical examples and applications, sometimes in surprising places. Many of these applications are unique or put a new spin on things. The link to computing helps make many of the topics tangible to a general audience.”–Matt Lane, creator of the Math Goes Pop! Blog

 

#PiDay Activity: Using chocolate chips to calculate the value of pi

Chartier_MathTry this fun Pi Day activity this year. Mathematician Tim Chartier has a recipe that is equal parts delicious and educational. Using chocolate chips and the handy print-outs below, mathematicians of all ages can calculate the value of pi. Start with the Simple as Pi recipe, then graduate to the Death by Chocolate Pi recipe. Take it to the next level by making larger grids at home. If you try this experiment, take a picture and send it in and we’ll post it here.

Download: Simple as Pi [Word document]
Download: Death by Chocolate Pi [Word document]

For details on the math behind this experiment please read the article below which is cross-posted from Tim’s personal blog. And if you like stuff like this, please check out his new book Math Bytes: Google Bombs, Chocolate-Covered Pi, and Other Cool Bits in Computing.

For more Pi Day features from Princeton University Press, please click here.


 

Chocolate Chip Pi

How can a kiss help us learn Calculus? If you sit and reflect on answers to this question, you are likely to journey down a mental road different than the one we will traverse. We will indeed use a kiss to motivate a central idea of Calculus, but it will be a Hershey kiss! In fact, we will have a small kiss, more like a peck on the cheek, as we will use white and milk chocolate chips. The math lies in how we choose which type of chip to use in our computation.

Let’s start with a simple chocolatey problem that will open a door to ideas of Calculus. A Hershey’s chocolate bar, as seen below, is 2.25 by 5.5 inches. We’ll ignore the depth of the bar and consider only a 2D projection. So, the area of the bar equals the product of 2.25 and 5.5 which is 12.375 square inches.

Note that twelve smaller rectangles comprise a Hershey bar. Suppose I eat 3 of them. How much area remains? We could find the area of each small rectangle. The total height of the bar is 2.25 inches. So, one smaller rectangle has a height of 2.25/3 = 0.75 inches. Similarly, a smaller rectangle has a width of 5.5/4 = 1.375. Thus, a rectangular piece of the bar has an area of 1.03125, which enables us to calculate the remaining uneaten bar to have an area of 9(1.03125) = 9.28125 square inches.

Let’s try another approach. Remember that the total area of the bar is 12.375. Nine of the twelve rectangular pieces remain. Therefore, 9/12ths of the bar remains. I can find the remaining area simply be computing 9/12*(12.375) = 9.28125. Notice how much easier this is than the first method. We’ll use this idea to estimate the value of π with chocolate, but this time we’ll use chocolate chips!

Let’s compute the area of a quarter circle of unit radius, which equals π/4 since the full circle has an area of π. Rather than find the exact area, let’s estimate. We’ll break our region into squares as seen below.

This is where the math enters. We will color the squares red or white. Let’s choose to color a square red if the upper right-hand corner of the square is in the shaded region and leave it white otherwise, which produces:

Notice, we could have made other choices. We could color a square red if the upper left-hand corner or even middle of the square is under the curve. Some choices will lead to more accurate estimates than others for a given curve. What choice would you make?

Again, the quarter circle had unit radius so our outer square is 1 by 1. Since eight of the 16 squares are filled, the total shaded area is 8/16.

How can such a grid of red and white squares yield an estimate of π? In the grid above, notice that 8/16 or 1/2 of the area is shaded red. This is also an approximation to the area of the quarter circle. So, 1/2 is our current approximation to π/4. So, π/4 ≈ 1/2. Solving for π we see that π ≈ 4*(1/2) = 2. Goodness, not a great estimate! Using more squares will lead to less error and a better estimate. For example, imagine using the grid below:

Where’s the chocolate? Rather than shading a square, we will place a milk chocolate chip on a square we would have colored red and a white chocolate chip on a region that would have been white. To begin, the six by six grid on the left becomes the chocolate chip mosaic we see on the right, which uses 14 white chocolate of the total 36 chips. So, our estimate of π is 2.4444. We are off by about 0.697.

Next, we move to an 11 by 11 grid of chocolate chips. If you count carefully, we use 83 milk chocolate chips of the 121 total. This gives us an estimate of 2.7438 for π, which correlates to an error of about 0.378.

Finally, with the help of public school teachers in my seminar Math through Popular Culture for the Charlotte Teachers Institute, we placed chocolate chips on a 54 by 54 grid. In the end, we used 2232 milk chocolate chips giving an estimate of 3.0617 having an error of 0.0799.

What do you notice is happening to the error as we reduce the size of the squares? Indeed, our estimates are converging to the exact area. Here lies a fundamental concept of Calculus. If we were able to construct such chocolate chip mosaics with grids of ever increasing size, then we would converge to the exact area. Said another way, as the area of the squares approaches zero, the limit of our estimates will converge to π. Keep in mind, we would need an infinite number of chocolate chips to estimate π exactly, which is a very irrational thing to do!

And finally, here is our group from the CTI seminar along with Austin Totty, a senior math major at Davidson College who helped present these ideas and lead the activity, with our chocolatey estimate for π.

March Mathness Winner

Davidson College student, Jane Gribble, was our March Mathness winner this year. Below she explains how she filled in her bracket.

 


 

Gribble

I love basketball – Davidson College basketball. As a Davidson College cheerleader I have an enormous amount of school pride, especially when it comes to our basketball team. However, outside of Davidson College I know little to nothing about college basketball. I knew that UNC Chapel Hill was having a tough season because this is my sister’s alma mater. Also, I knew that New Mexico, Gonzaga, Duke, and Montana were all likely teams for the NCAA tournament because we had played these non-conference teams during our season and these were the most talked about non-conference games around campus. My name is Jane Gribble. I am a junior mathematics major and this is the first year I completed a bracket.

In Dr. Tim Chartier’s MAT 210 – Mathematical Modeling course we discussed sports ranking using the Colley method and the Massey method. We were given the opportunity to apply our new knowledge of sports ranking in the NCAA Tournament Challenge. Since Davidson College was participating in the tournament my focus was on one game, the Davidson/Marquette game in Lexington, KY. When we traveled to KY I thought I had missed my opportunity to fill out a bracket, but one of my classmates was also traveling for the game with the Davidson College Pep Band and had the modeling program on his computer. We completed our brackets in the hotel lobby in Kentucky the night before our game.

My bracket used the Massey method because in previous years it has had better success than the Colley method. I decided to submit only one bracket, a bracket solely based on math (partially because I know little about college basketball). As a cheerleader and a prideful student it upset me to have Davidson losing against Marquette the following night, but I wasn’t going to let a math model crush my personal dreams of success in the tournament.  The home games were weighted as .5 (it would have been 1 if it was an unweighted model) to take into account home court advantage. Similarly, away games were weighted as 1.5 and neutral games as 1. Also, the season was segmented into 6 equal sections. I believe games at the end of the season are more important than games at the beginning of the season because teams change throughout the year and the last games give the best perspective of the teams going into the tournament. There was no real reason for the numbers chosen, other than they increased each segment. The 6 equal sections were weighted: .4, .6, .8, 1, 1.5, and 2. With these weights in the Massey method my model correctly predicted the Minnesota upset, but missed the Ole Miss, LaSalle, Harvard, and Florida Gulf upsets.

After Davidson’s tragic loss I could not watch anymore basketball for a while. I even forgot that my bracket was in the competition. I only started paying attention to the brackets when a friend in the same competition congratulated me on being second going into the Elite 8; my math based bracket was in the top 10 percent of all the brackets. Once he told me my bracket had a chance of winning, I paid attention to the rest of the games to see how my bracket was doing in the competition. After Davidson’s loss against Louisville last year in the tournament I never wanted to cheer for Louisville. To my surprise, I went into the final game this year cheering for Louisville because my model had Louisville winning it all. I was not cheering for Louisville because of any connections with the team, but was cheering to receive a free ice cream cone, a prize that our local Ben and Jerry’s donates to the winner of  Dr. Chartier’s class pool.

Next year I hope to compete in the NCAA tournament challenge again. This year I greatly enjoyed the experience and want to continuing submitting brackets for the tournament. Next year I will submit one bracket that uses the exact weightings of my bracket this year to see how it compares from year to year. This year I wanted to submit a math bracket that looked at teams who had injuries throughout the season. My motivation for this was Davidson’s player Clint Mann. Clint had to sit out many games towards the end of the season because of a concussion, but he had recovered in time for the NCAA tournament. I thought that our wins during the time without Clint showed our strengths as a team. Unfortunately this year I ran out of time to code this additional weighting. Hopefully next year my submissions will include a bracket using the weights from this year, a bracket that includes weights for teams with injured team members, and another bracket with varying weights.