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Googol, Kasner, and Milton Sirotta

Date: 07/14/99 at 16:55:09
From: Melanie
Subject: Powers of 10

Who coined the phrase "googleplex," and when? I have used several 
search engines and they have the definition, but not the origin. 

Thank you for your consideration,

Date: 07/15/99 at 11:59:13
From: Doctor Peterson
Subject: Re: Powers of 10

Hi, Melanie.

We get questions about this frequently, so I did a little extra 
research to find the details beyond what's in our archives.

Here's a page on the Web that tells about the origin of the words 
googol and googolplex:

How Many? A Dictionary of Units of Measurement   

This says:


a unit of quantity equal to 10^100 (1 followed by 100 zeroes). The 
googol was invented by the American mathematician Edward Kasner (1878-
1955) in 1938. According to the story, Kasner asked his nephew Milton 
Sirotta, who was then 8 years old, what name he would give to a really 
large number, and "googol" was Milton's response. Kasner also defined 
the googolplex, equal to 10^googol, that is, 1 followed by a googol of 
zeroes. These inventions caught the public's fancy and are often 
mentioned in discussions of very large numbers."

A slightly different version is in


which says:

"The American mathematician Edward Kasner once asked his nine-year-old 
nephew to invent a name for a very large number, ten to the power of 
one hundred; and the boy called it a googol. He thought this was a 
number to overflow people's minds, being bigger than anything that can 
ever be put into words. Another mathematician then shot back with 
googolplex, and defined it to be 10 to the power of googol."

Here's a review of the 1940 book in which Kasner discussed the googol:

Edward Kasner and James Newman. Mathematics and the Imagination   

Also check out our Dr. Math FAQ on large numbers:   

Summing up, the googol was named by Milton Sirotta, and the googolplex 
by his uncle Edward Kasner, who I suspect had set Milton up by asking 
for a name for the googol, just so he could name something incredibly 

Incidentally, you'll find that the googol can just as well be called 
"10 duotrigintillion" following the (more or less) standard 
conventions for naming large numbers; googol is just the fun name, 
which allows us to name "googolplex" easily; and if a mathematician 
or scientist ever had occasion to use either number, they would just 
call them 10^100 and 10^10^100 because numbers are much easier to work 
with than names.

- Doctor Peterson, The Math Forum   
Associated Topics:
Elementary Large Numbers
Elementary Math History/Biography
Middle School History/Biography

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