Q. Without looking it up, do you know the value of the Greek letter "pi," representing the relationship between a circle and its diameter?

A. Most people today can tell you pi equals roughly 3, or 3.14 to be more precise, or 3.1416 to be even more so, says astronomer Bob Berman in "Astronomy" magazine. In the Old Testament, a round altar is said to be "10 cubits from edge to edge and 30 cubits around," though the more correct circumference figure would have been 31½.

Believe it or not, of all the countless ways to approximate the most prolific irrational number in the universe, there are none quite as interesting or as surprisingly satisfying as throwing perfectly good food around your kitchen. In fewer steps than it takes to circumscribe your house in a circle of baguettes, you, too, can easily add a slice of pi into your dinner menu tonight. The best part is...it really works!

The number pi is the ratio between the circumference of a circle and its diameter. It's approximately equal to 3.14159265, although the digits go on forever. Some mathematicians are obsessed with computing pi to more and more digits. In the year 1610, a German mathematician computed pi to 35 digits. In 1789, a Slovene mathematician computed pi to 140 digits. In 2002, frantic Japanese mathematicians used a supercomputer to accurately compute pi to 1,241,100,000,000 digits. Based on all this effort, you might assume that it'd be useful to know a trillion digits of pi. However, if you had a circle the size of the observable universe, and you wanted to compute its circumference with an accuracy equal to the size of a proton, the number of digits of pi that you'd need is only 50.

Kate Bush has released a new album "Aerial", on which she sings around the first 100 digits of Pi.

Sweet and gentle sensitive man With an obsessive nature and deep fascination For numbers And a complete infatuation with the calculation Of PI

Oh he love, he love, he love He does love his numbers And they run, they run, they run him In a great big circle In a circle of infinity

3.1415926535 897932 3846 264 338 3279

Oh he love, he love, he love He does love his numbers And they run, they run, they run him In a great big circle In a circle of infinity But he must, he must, he must Put a number to it