Where does “kuutisenkymmentä” come from?

kuutisenkymmentä (Finnish) comes from Finnish kuutisen, from Finnish -isen, from Finnish -inen, from Finnish -uus, from Proto-Finnic -uc — -ness, -hood.

kuutisenkymmentä (Finnish): about sixty

Definitions

about sixty

Ancestry of “kuutisenkymmentä”, step by step

kuutisenkymmentä traces back through two separate lines of ancestry.

via Finnish kuutisen

Step	Language	Word	Meaning
1	Finnish	kuutisen	about six
2	Finnish	-isen	forms adverbs from numerals to represent an...
3	Finnish	-inen	-like, -ous, -y; -en; Creates adjectives from...
4	Finnish	-uus	Forms nouns from adjectives, expressing a quality
5	Proto-Finnic	-uc	-ness, -hood

via Finnish kymmen

Step	Language	Word	Meaning
1	Finnish	kymmen	ten; decade
2	Proto-Finnic	kümmen	ten; decade, group of ten

Every word from Proto-Finnic -uc →Every word from Finnish -inen →Every word from Finnish -uus →