The day celebrates the number 𝛑, 3.14, and is also Albert Einstein's ... mathematicians have calculated it out to 22 trillion digits. The doodle celebrating that number is a salted caramel ...

It’s Pi Day (March 14, 3.14 — get it?), and to mark this occasion, today’s Google Doodle — that interactive ... is a mathematical constant; i.e. a number that never actually ends.