Guest Blog

## How Many Digits of Pi Do You Really Need to Know? Find Out with This Bar Bet

A physicist or engineer who uses π (pi) in numerical calculations may need to have access to 5 or 15 decimal place approximations to this special number, but most of us—mathematicians included—don’t need to know more (decimal-wise) than the fact that it’s roughly 3.14. Yet there is an inexplicable nerdy subculture far removed from real [...]

Observations

## How Much Pi Do You Need?

I hope you’re ready for your big Pi Approximation Day party tomorrow. You might have observed Pi Day on March 14. It gets its name from 3.14, the first three digits of the ratio of a circle’s circumference to its diameter. Always on the lookout for excuses to eat pie, some geeky math types also [...]

Observations

## Does Pi Encode Shakespeare’s Plays? [Video]

Yesterday was Pi Day (3.14, approximately), and appropriately enough comes this analysis of the irrational number by Vi Hart, a recreational “mathemusician” at Khan Academy. You might remember her from her viral video about love and self-delusion on the Mobius strip. In the video below, she explores—in seven sonnets—whether “Romeo and Juliet” and other of [...]

Roots of Unity

## What’s so Great about Continued Fractions?

The more I learn about continued fractions, the more enamored I am with them. Last week, when I wrote about how much better continued fractions are than the arbitrary decimal digits we usually use to describe numbers, I mentioned that continued fractions tell us the “best approximations” of irrational numbers. Continued fractions are just fractions [...]

Roots of Unity

## Don’t Recite Digits to Celebrate Pi. Recite Its Continued Fraction Instead.

The digits of pi reciting contest is an all-too-common Pi Day event. And as this year is a once-in-a-century confluence of month/day/year with the first few decimal digits of pi, we might be in for more of those than usual. Our 10 fingers make decimal digits a natural choice, but if we were capybaras or [...]

Roots of Unity

## A Different Pi for Pi Day

The symbol π is overloaded in math: depending on context and capitalization, π could be the constant we all know and love (or hate), a projection, a product, or a function. There’s plenty of stuff to read about the circle constant, so today I’m writing about one of those other π’s. Today’s π is the [...]

Roots of Unity

## How Much Pi Do You Need?

I am traveling for most of July. I hope you enjoy this post from the past, which originally appeared on the Observations blog on July 21, 2012. I hope you’re ready for your big Pi Approximation Day party! You might have observed Pi Day on March 14. It gets its name from 3.14, the first three [...]

Roots of Unity

## Big Numbers Are Big

Today I have a piece in Slate about that pi meme that’s been going around. According to the meme, your life story is encoded in pi somewhere. My life story would probably include the word “Evelyn” at some point. (I’m going out on a limb, but stay with me.) In a code that assigns the [...]

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