Ten decimals are sufficient to give the diameter of the earth to the fraction of an inch.

Related:

• Give an Inch,
  Take a Smile...
• Never give
  an inch...
• Give a skeptic an inch and he'll
  measure it...
• TEN-INCH ERECTION --
  Double-digit inflation...
• Give a man an inch,
  and he thinks he's a ruler...
• Give a woman an inch and she'll try to park a car
  in it...
• Give a woman an inch and she thinks she's a
  ruler...
• Give weeds an inch and they'll take
  a yard...