What number was first used by nine year old Milton Sirotta in 1940?

The number first used by nine-year-old Milton Sirotta in 1940 is known as a "googol." A googol is represented as 10^100, a 1 followed by 100 zeros. This term was introduced by mathematician Edward Kasner, who asked his young nephew, Milton Sirotta, to come up with a name for such a large number.