Roots of Unity

How the Simpsons (And You) Can Multiply by Seven Using Your Fingers

When I tutored elementary school math, one of my favorite things to show the kids was how to multiply by 9 using their fingers. (I apologize, but this trick assumes that you have five fingers on each hand. Later you’ll see how to adapt it if you have nonstandard hands.) Here’s how the finger rule [...]

Roots of Unity

Carnival of Mathematics #103

Welcome to the 103rd Carnival of Mathematics! The number 103 is prime, and it’s the “older” twin of a pair of twin primes as well—or is it the “younger” twin because it comes later? Regardless, 101 and 103 are twin primes. According to Tanya Khovanova’s site Number Gossip, 103 is not only prime and happy [...]

Roots of Unity

Can a Closed Set Be Open? Can an Open Set Be Closed? When Math and Language Collide

I gave my first midterm last week. I’m teaching a roughly junior level class for math majors, one of their first classes that is mostly focused on proofs rather than computations or algorithms. It is more abstract than most math classes they’ve taken up to this point. I love teaching this class because a class [...]

Roots of Unity

Step Right Up! It’s the Carnival of Mathematics!

The Carnival of Mathematics is a monthly blogging round-up of fun math-related blog posts organized by the friendly folks of the Aperiodical. This month, Michelle Blair of My Summation is hosting Carnival #102. Head on over to find some gems you may have missed in the last month. (Hint: you should check out the sonnets [...]

Roots of Unity

Blackboards Make You Stupid (Or Is It Just Me?)

I just finished my first week teaching after a few years out of the classroom. Whenever I teach, I’m struck by how much detail I need to put in my notes to make sure I don’t say something absolutely ridiculous when I’m in front of the class. Even with careful preparation, I sometimes arrive back [...]

Roots of Unity

Mathematics, Live: A Conversation with Laura DeMarco and Amie Wilkinson

This year I’ve been co-writing “Mathematics, Live,” an interview series for the Association for Women in Mathematics newsletter. In my interviews I’m “listening in” on conversations between pairs of female mathematicians. The first interview appeared in the May/June issue of the newsletter (password required). In it, I talked with mathematicians Laura DeMarco of the University [...]

Roots of Unity

Image: Design Shack In the current issue of the Association for Women in Mathematics newsletter (password required), Anne Carlill asks where the female mathematicians are on Twitter: “I found that the only female mathematicians or math educators I followed were Nalini Joshi in Sydney and Fawn Nguyen in California. In contrast there are about 15 [...]