Where does “sexāgintā” come from?

sexāgintā (Latin) comes from Proto-Indo-European sweḱsḱomt, from Proto-Indo-European swéḱs-dḱomt — six-ten.

Ancestry of “sexāgintā”, step by step

Step	Language	Word	Meaning
1	Proto-Indo-European	sweḱsḱomt	—
2	Proto-Indo-European	swéḱs-dḱomt	six-ten

sexāgintā — Etymology, Origin & Word History | Etymology Explorer