It’s not the loneliest number, but it might be the most famous. Pi (or π) is commonly defined as the ratio of the circumference of a circle to its diameter. π has been calculated to trillions of digits, but most people just know the first few, namely 3.14—hence, Pi Day, celebrated every year on March 14th (3/14, get it?).
If you haven’t already rolled your eyes and closed this tab, you might be the type who’d enjoy reading more about Pi and/or math in general, so here are some librarian recommendations. And don’t forget to enjoy a slice of Pi(e) while you’re at it.
Recommended: Books About Pi
Recommended: Books About Math