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.
Transcend decimals as you celebrate this transcendental number
Tired of the circle constant? The prime counting function π(x) is an alternative way to celebrate everyone's favorite Greek letter that sounds like a dessert.
Continued fractions are objectively the best in approximation technology