Here is my advice to students who need to ask their professor for a letter of recommendation. Ask your professor nicely and politely. You do not have to ask the professor in person, but do not ask the professor in a quickly jotted, informal email in all lower case! Early, early, early. It takes time…
Happy New Year!
This is one day late, but worth posting despite that, I think. Happy New Year! From Abstruse Goose: Happy Zeno Year
Definition of continuity video
Thank you to Dansmath for turning me on the website xtranormal. It allows you to create your own animated videos. It is easy and fun. You can choose the characters, the scene, the camera angles, the gestures and facial expression, music, etc. They do the voices for you—you just type the script. Here are some of Dan’s videos….
2009 Times Square New Year’s Eve Ball
We can look forward to a very mathematical New Year’s eve ball in Times Square this year. According to the Times Square website: The new Times Square New Year’s Eve Ball is a 12 foot geodesic sphere, double the size of previous Balls, and weighs 11,875 pounds. Covered in 2,668 Waterford Crystals and powered by…
Materials for a knot theory class
This is a call for help—or for suggestions, at least. I’m teaching a knot theory class next semester. I’m looking for good props to use in the class to make knots. I would like to be able to make knots such as the following (and have my students do so as well). I suppose the…
46th Carnival of Mathematics
The 46th Carnival of Mathematics is now online, hosted by Walking Randomly. I was happy to see one my blog posts listed there. Cool! These carnivals are great. I’ll have to look into how to host one in the future. I don’t know who runs them.
A 10-adic number that is a zero divisor
A few weeks ago I wrote about p-adic numbers. I mentioned that if p is not prime, then the p-adic numbers can have zero divisors; that is, there are nonzero numbers and such that . Today Foxmaths! wrote about a 10-adic number (although not using that terminology) such that (in other words is an idempotent…
The importance of definitions: chance of rain
Tomorrow’s weather forecast for Carlisle, PA, is: Windy with showers. High 58F. Winds SW at 20 to 30 mph. Chance of rain 40%. First of all, 58 degrees on December 28? Sweet! But what does “chance of rain 40%” mean? Does it mean that there is a 40% chance that it will rain at my…
How to curve an exam and assign grades
We have all given exams where the grades end up lower than we hoped. A curve is in order. How do we do it? In this post I share my thoughts on when you should (or should not) curve an exam. I give ten sample curving techniques, including pros and cons of each, I explain…
Multiple choice questions in mathematics
It must be exam time. Discussions of multiple-choice test questions are in the air. Terrence Tao has a nice post about multiple choice questions in mathematics (it is a follow-up to this post of his). He writes about the pros and cons of giving multiple choice questions in a mathematics class. For example: These quizzes give a…
David Richeson: Division by Zero 