** Calculus Teacher Makes the Big Times**

**Yitang Zhang**

Photo by Peter Bohler – The New Yorker, February 2, 2015

Before turning to this month’s posts, I thought you might be interested in this. There is an interesting profile of Yitang Zhang in this week’s *The New Yorker* magazine by Alex Wilkinson. Mr. Zhang is a mathematician whose interest is “bound gaps” a problem in number theory on prime numbers. He is a part-time calculus teacher at the University of New Hampshire. He has won several prizes including a MacArthur award.

The profile is entitled The Pursuit if Beauty.

Wilkinson also made a short video explaining the “bound gaps” problem.

**February**

This month our previous posts finish a series on accumulation started in January and includes notes on power series. I have a few new post planned for February. Towards of the end of the month I plan to post a list of the previous posts on reviewing for the AP exams. As usual the four posts directly below are the most popular from previous Februarys. The most popular by a factor of about 50 (really) is the one on Error Bounds followed by iPads.

As always, please feel free to comment, question, or ask questions. I can use some suggestions about what you would like me to write about. My email address is lnmcmullin@aol.com. Notice, I’m a natural logarithm.

Thanks in advance.

**Posts from past Februarys**

February 2, 2013: Accumulation and Differential Equations **Accumulation 6: Differential equations **

February 4, 2013: Painting a Point **Accumulation 7: An application (of paint) **

February 8, 2013: Introducing Power Series 1

February 11, 2013: Introducing Power Series 2

February 13, 2013: Introducing Power Series 3

February 15, 2013 New Series from Old 1

February 18, 2013: New Series from Old 2

February 20, 2013: New Series from Old 3

February 22, 2013: Error Bounds

February 17, 2014 iPads