numeration system vs system of numeration

numeration system and system of numeration both are nouns.

Word	Noun	Adjective	Verb	Adverb
numeration system	Yes	No	No	No
system of numeration	Yes	No	No	No

As nouns, numeration system and system of numeration are synonyms defined as:

numeration system and system of numeration: any notation for the representation of numbers

Other synonyms of numeration system include number representation system, number system.

numeration system (noun)	system of numeration (noun)
any notation for the representation of numbers	any notation for the representation of numbers