February 9, 2010, 1:34 pm

By Robert Talbert

I learned the following trick for memorizing the value of *e* from my colleague, Gene White. It never fails to impress calculus students (given a wide enough definition of “impress”).

Start by carefully looking at this picture:

That’s a **20** dollar bill, so memorize “2″ and put down the decimal point.

The picture on the bill is of Andrew Jackson. He was our **seventh** President, so put a “7″ after the decimal point to get** 2.7.**

Jackson was elected in **1828**, so put down “1828″ next. Since there’s a 2 in front of the decimal place, put “1828″ a second time. We’re now up to **2.718281828**.

Now look at the red square over Jackson’s face. The diagonal creates two congruent right triangles with angle measures **45, 90, and 45**. So, add on 459045 to get **2.718281828459045**. And that’s *e* to 15 places.

I’m open to suggestions on how to memorize more of the digits.

August 13, 2008, 2:15 pm

By Robert Talbert

May 1, 2008, 8:03 pm

By Robert Talbert

Driving in to work this morning, I suddenly felt my vision go blurry to the point where I literally couldn’t see anything. Fortunately, I was able to pull off the road into the parking lot of a small office building before causing an accident. After I stopped and waited for the blurriness to subside, the first thing I saw was the mailbox for the office building, which had a street number of: 2048. Rather than wonder what the crap was wrong with my eyesight, or frantically try to decide whether to go see a doctor on the spot, instead the first thing I thought was hey: That’s \(2^{11}\).

Then, after making it to work with no more blurry vision attacks, I walked up to my office — the same office I have been entering and exiting since summer 2001 — and looked at the office number and saw it: room 128. Of course, I’ve never had a problem remembering my office number But for the first…

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