Through Math for America, I am part of an on-going collaboration with the New York Times Learning Network. My latest contribution, a Test Yourself quiz-question, can be found here:
https://learning.blogs.nytimes.com/2011/06/01/test-yourself-math-june-1-2011/
This problem is based on the dwindling availability of hospstal emergency rooms around the country.
In an attempt to rate the various Major League Baseball stadiums around the country, Nate Silver looked at the user ratings from online review site Yelp. Noting that every ballpark has at least several hundred user reviews, Silver compiled the data from Yelp’s 1 to 5 rating system to create an ordering of the stadiums. Once complete, the list creates a natural starting point to investigate questions like “Is ballpark satisfaction correlated with team performance?” and “How valuable is a retractable-roof stadium?”
Silver also provides the standard deviation for the ratings for each ballpark and explains the significance. Standard deviation is a measure of the dispersion of data, so a higher deviation means more extreme ratings.
A great, fun little project! What else can we rate using available user ratings?
Read the full article here.
This is a great tool for plotting vector fields:
http://dlippman.imathas.com/g1/fullgrapher2d.html
You can also plot functions of all kinds: implicit, explicit, polar, parametric, etc. In addition, you can plot several different graphs simultaneously (say, a vector field and a set of flow lines), and you can modify each graph individually.
I found this very helpful is constructing a recent test!
I find my blog to be a very useful teaching tool. It’s full of resources for students to explore, and after doing so they often follow up in class with interesting questions and comments. The blog helps extend our mathematical conversations beyond the classroom. Sometimes, it works too well.
In a recent discussion on probability, we considered the following question:
Suppose you randomly choose a positive integer. What is the probability that the number you choose is divisible by five?
The students thought about the question and discussed their ideas. I asked for their thoughts. The usual good answers came out (
“The answer is zero,” he said. “Although there are infinitely many multiples of five and infinitely many total integers, the probability is zero because a small infinity divided by a big infinity is zero.”
“A small infinity divided by a big infinity is zero?” I responded, trying to appear as perplexed as possible. “That sounds kind of crazy to me. What does that even mean?” I tried to stir up the anti-zero sentiment in the room.
The student persisted. “According to you, a small infinity divided by a big infinity is zero.”
“That doesn’t sound like something I’d say,” I said, which is what I say when students remember something I wish they hadn’t. I usually get away with it. Not this time.
“You didn’t say it,” replied the student. “You wrote it on your blog.”
In a rare moment, I had no response. What could I say? I did write it on my blog. I had nowhere to hide.
The class celebrated this clear and decisive victory.
