system of numeration vs numeration system

system of numeration and numeration system both are nouns.

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

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

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

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

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