## Wednesday, June 17, 2015

### Carnival of Mathematics Number 123 - Part II

6/17/2015

Carnival of Mathematics, Number 123, Part II

OK now, it's time to pull out your E-tickets.

The following submissions have been submitted by my mathatological cohorts:

(1)  "A Circle in the Corner of a Circle", from David Leese.  An interesting and simple geometry question, that expands out into a complicated formula, but has an elegant solution.  http://davechessgames.blogspot.com/2015/03/geometry-circle-in-corner-of-circle.html

(2) "Generalization of Divisibility Rules for Primes", from Ganit Charcha, and submitted by Debapriyay Mukhopadhyay.  This article provides an easy to understand algorithm to test whether a given number N is divisible by a prime p (where p is not equal to 2 or 5) or not. Nicely written and easy to understand.  This will be very helpful for students as well.
http://www.ganitcharcha.com/view-article-Generalization-of-Divisibility-Rules-for-Primes.html

(3) Katie Steckles from Aperiodical.com submitted a link to an article talking about different voting systems "What Does Eurovision 2015 Tell Us about Voting Systems?".  It can be read at:

(4) A new Fibonacci Clock is available (completed or as a kit).  I wish that I had one of these when I was still teaching.  See pictures and directions on how to tell time using a Fibonacci Clock at: http://www.theguardian.com/science/alexs-adventures-in-numberland/2015/may/09/fibonacci-clock-can-you-tell-the-time-on-the-worlds-most-stylish-nerd-timepiece

Easy as 1, "1, 2, 3", 5, ...

(5)  Manan Shah has sent us this link for "Pizza Metrics".  I'm always amused when I hear people inquiring about the size of a pizza pie by asking how many slices are present. Mildly in their defense, not all pizza places actually give a diameter for how big their pizza pies are.   http://mathmisery.com/wp/2015/06/02/comic-28-pizza-metric/.

(6)  Dan McQuillan forwards this like to "It's a Mean Value Theorem."  This post features a couple of elementary and interesting applications of the Mean Value Theorem.  It also illustrates how playing with examples--and finding a really good example, can help understand a problem well enough to lead to a full solution.  http://voices.norwich.edu/daniel-mcquillan/2015/06/02/its-a-mean-value-theorem/.

(7) Mike Lawler sends this: I stumbled on the book "Fractals Chaos Power Laws" via a Steven Strogatz tweet - more details here: https://mikesmathpage.wordpress.com/2015/05/23/a-super-fun-fractal-project-for-tomorrow/  The book has a neat example about fractal dimension which turned into a super fun math project with my kids.

(8) Hermino L.A. submitted this information on "The Awkward Question".  Sometimes it's quite difficult to get a truthful answer from people in surveys. Fortunately, some mathematical methods have been created to overcome the reluctance of people to answer some awkward questions.  http://mathsball.blogspot.com/2015/06/the-awkward-question.html

(9) Thomas OlĂ©ron Evans sends us this link about "Fractal Factorials". http://www.mathistopheles.co.uk/2015/05/14/fractal-factorials/  "I came across some rather beautiful fractals that I was not previously aware of when iterating the factorial function across the complex plane."

I guess all good things come to an end.  It's time to go home now.  Drive save and come back soon.

The next Carnival (Carnival of Mathematics number 124) will in July 2015, and will be hosted by Manjil at Gonit Sora.

For more information about past or present or future Carnivals please visit the Aperiodical Carnival of Mathematics page at: http://aperiodical.com/carnival-of-mathematics/.

David