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The -yllion system is a fabricated system invented by Donald Knuth for naming large numbers.[1]

Usage Edit

Numbers up to 999 are named as they are normally.

Numbers from 1000 to 9999 are written without a comma and pronounced "a-ty b hundred c-ty d" for the number abcd. For example, 7283 is pronounced "seventy-two hundred eighty-three." The word thousand is not used in this system.

\(10^4\) is called the quadmillillion. All numbers from the quadmillillion up to 9999 are written with a comma between the ten thousands and thousands place. For example, 32767 would be written 3[1]2767.

Such numbers are pronounced like so:

  • 45,7839 is pronounced "forty-five myriad seventy-eight hundred thirty-nine."
  • 2423,3000 is pronounced "twenty-four hundred twenty-three myriad thirty hundred."
  • 9999,9999 is pronounced "ninety-nine hundred ninety-nine myriad ninety-nine hundred ninety-nine."

\(10^8\) is called the quadmicrillion. It is written 1[2]0000[1]0000. Note that a new punctuation mark, a semicolon, was used to represent the quadmillillions place. Numbers up to quadmillillion are named in the same way as the above numbers are pronounced: each group of four digits is pronounced as written above, and the commas are pronounced "quadmillillion." The only difference is that the semicolon ([n]) is pronounced "quadmillillion."

\(10^{16}\) is called the quadnanillion. It is written 1[3]0000[2]0000[1]0000. Note that a new punctuation mark, a colon, was used to represent the byllions place. Numbers up to 9999[1]9999 are pronounced as above, but the colon ([2]) is pronounced "quadmicrillion."

Continuing in this method, we have n-yllion \(= 10^{4}\), allowing the quadpicillion, quadfemtillion, etc.

Sources Edit

  1. The Bower's' quad-illion Notation - Large Numbers (page 2) at MROB
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