# Focus on Math

## Helping children become mathematicians!

### Happy Pi Day Everyone! March 14, 2014

Filed under: General Math — Focus on Math @ 11:36 am

π is one of the most widely-known mathematical constants both inside and outside the mathematics/scientific community and it has been around for a very long time!

The ratio of the circumference to the diameter of a circle is constant (namely, pi) and has been recognized for as long as we have written records.

A ratio of 3:1 appears in the following biblical verse: “And he made a molten sea, ten cubits from the one brim to the other: it was round all about, and his height was five cubits: and a line of thirty cubits did compass it about.”  (I Kings 7, 23; II Chronicles 4, 2.)

The ancient Babylonians generally calculated the area of a circle by taking 3 times the square of its radius (=3), but one Old Babylonian tablet (from ca. 1900-1680 BC) indicates a value of 3.125 for pi.

π is commonly defined as the ratio of a circle‘s circumference C to its diameter d.

The ratio C/d is constant, regardless of the circle’s size. For example, if a circle has twice the diameter of another circle it will also have twice the circumference, preserving the ratio C/d.

Of course, there is humor in math, so here’s the joke of the day:

What is the official animal of Pi Day? Why, the pi-thon, of course!

Mathematically yours on the “mathy” day,

Carollee