The symbol is overloaded in math: depending on context and capitalization, could be the constant we all know and love (or hate), a projection, a product, or a function.
A physicist or engineer who uses (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.
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.
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.