3/14 is that one magical day where we can celebrate Pi, 3.1415926535 … you get the idea. Here are a few tidbits about this “magical” irrational number:

• Ten decimals are sufficient to give the circumference of the earth to a fraction of an inch.
• You can find your hat size by measuring the circumference of your head, divide by Pi, then round off to the nearest 1/8th inch.
• The earliest known record of an individual realizing that the ratio between a circle’s circumference and it’s diameter is constant comes from an Egyptian scribe named Ahmes in 1650 BCE.
• The Romans often stubbornly used an estimation of 3 and 1/8th for Pi (even though they clearly knew that 3 and 1/7th is a closer estimation). They reasoned that it was eaiser for their legions to determine 1/2 of 1/2 of 1/2 instead of 1/7th.

Most of this information is from The Joy Of Pi by David Blatner. Take a closer look at the Pi image on the right.