Through Math for America, I am part of an ongoing collaboration with the New York Times Learning Network. My latest contribution, a Test Yourself quiz-question, can be found here
Test Yourself — Math, April 30th, 2014
This question was inspired by the recent article What You Don’t Know About Financial Aid (but Should), and addresses the question “Approximately what percentage of income does an average family pay to send a child to college?”
A recent delivery came with an unexpected bonus.
A diagram illustrating the geometric relationship between the length and the width of the box!
Of course, the equation 
I did a quick search and found the standard pallet size to be 48 inches by 40 inches. So my best guess is that 
Today we celebrate a Derangement Day! Usually I call a day like today a permutation day because the digits of the day and month can be rearranged to form the year, but there’s something extra special about today’s date:
The numbers of the month and day are a derangement of the year: that is, they are a permutation of the digits of the year in which no digit remains in its original place!
Derangements pop up in some interesting places, and are connected to many rich mathematical ideas. The question “How many derangements of n objects are there?” is a fun and classic application of the principle of inclusion-exclusion. Derangements also figure in to some calculations of e and rook polynomials.
So enjoy Derangement Day! Today, it’s ok to be totally out of order.
My complete interview with Steven Strogatz in the February 2014 issue of Math Horizons is now freely available.
Math Horizons makes one article from each issue freely available online, and I’m thrilled that for the February 2014 issue they chose my piece. Professor Strogatz is an acclaimed mathematician, writer, and teacher, and I think this interview captures a small amount of his enthusiasm, insight, and brilliance in all these fields.
The full interview is available as a PDF here. You can also find our conversation about math education in the Aftermath section of the magazine (posted online here), as well as some bonus material from our conversation here.
Today we celebrate another Permutation Day! I call days like today permutation days because the digits of the day and month can be rearranged to form the year.
Celebrate Permutation Day by mixing things up! Try doing things in a different order today. Just remember, for some operations, order definitely matters!