Jaume's presentation graphic (scale of the universe)

The Scale of the Universe
http://primaxstudio.com/stuff/scale_of_universe/index.php

Names of large numbers

English, like some other languages, treats large numerals as nouns (cf. "there were ten soldiers" and "there were a hundred soldiers"). Thus,dozens is preferred to tens, while hundreds and thousands are also completely acceptable.

Plurals of numbers differ according to how they are used. The following rules apply to dozen, score, hundred, thousand, million, and similar terms:

• When modified by a number, the plural is not inflected, that is, has no -s added. Hence one hundred, two hundred, etc. For vaguer large numbers, one may indifferently say several hundred or several hundreds.
• When used alone, or followed by a prepositional phrase, the plural is inflected: dozens of complaints, scores of people. However, eithercomplaints by the dozen or complaints by the dozens is acceptable (although differing in meaning).
• The preposition of is used when speaking of nonspecific items identified by pronouns: two hundred of these, three dozen of those. The ofis not used for a number of specific items: three hundred oscilloscopes. However, if the pronoun is included with the specific item, the ofis used: five million of those dollar bills.