Happy Right Triangle Day!
Today, on 12/9/15, we celebrate a favorite triangle: the 9-12-15 right triangle.
We know this triangle is right because the side lengths satisfy the Pythagorean Theorem.
We just recently celebrated this right triangle, but it will be a while before the date suggests another. So, enjoy being right today!
Today we celebrate the final Permutation Day of the year! I call days like today permutation days because the digits of the day and the 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!
I am excited to be hosting Math for America’s Master Teachers on Teaching (MT^2) event this December 10th at the Gerald D. Fischbaum auditorium.
MT^2 is an evening of short talks from MfA Master Teachers that are meant to inspire and challenge the MfA community. And it is a showcase of the passion and talent of that community, which now numbers nearly 1,000 teachers of math and science in New York City.
This will be the 4th annual MT^2, and the theme is Equality / Inequality. The evening’s lineup features eight talks from middle and high school math and science teachers offering a variety of different interpretations on the theme.
I have given talks in each of the first three MT^2’s: first, on the bad habits students learn from standardized tests; then on my relationship with change; and last year, about how to turn technology’s failures into teachable moments. While I enjoy the challenge of presenting, I am honored to be hosting this year’s event, and I look forward to an evening of great ideas.
And Math for America hopes to live-stream the event, so stay tuned!
Here is another installment in my series reviewing the NY State Regents exams in mathematics.
There is something of a history with Regents exams and the force of gravity.
An infamous problem years ago modeled a falling object with the quadratic function
This would imply that the acceleration due to gravity, or g, would be equal to 4 f/s², not the -32 f/s² we are accustomed to. This amusing error inspired my talk “g = 4, and Other Lies the Test Told Me“.
So, it was interesting to see projectile motion appear twice in the most recent round of math Regents exams. This is from the Integrated Algebra exam.
I was pleasantly surprised to see the proper coefficient!
And then I noticed a second appearance of gravity. This is from the Common Core Algebra exam.
Of course, I had to check. Kudos to the exam writers for looking up the actual force of gravity on the moon. If we’re going to go to the trouble of trying to establish “real world” contexts for these problems, we should make sure physical forces are accurately represented.
There is a lot of math to see when you look up, especially if you’re standing inside the skeleton of a hexagonal pyramid.
