STEVE INSKEEP, HOST:

Good morning. I'm Steve Inskeep. An old joke tells of a kid who comes home from school and says Pi R squared. His father says, what are they teaching you? Obviously, pies are round. The number Pi is 3.14. But that's an approximation. It's 3.1415926535, and it goes on forever. My daughter once memorized 100 digits. And Swiss scientists and a supercomputer recently calculated to trillions of decimal points.

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