The quantity twelve (12) is sometimes known as a dozen. It is in turn one twelfth of a gross.
Base-12 is known as duodecimal.
The Schoolhouse Rock segment "Little Twelvetoes" (Multiplication Rock, Season 1, Episode 11, 1973) discusses the usefulness of multiplying by 12: "Well, with twelve digits, I mean fingers, He probably would've invented two more digits When he invented his number system. Then, if he'd saved the zero for the end, He could count and multiply by 12's, Just as easily as you and I do by 10's. Now, if man Had been born with six fingers on each hand, He's probably count: 1, 2, 3, 4, 5, 6, 7, 8, 9, dek, el, do. Dek and el being two entirely new signs meaning 10 and 11 - single digits. And his 12, do, would've been written: one - zero. Get it? That'd be swell, to multiply by 12."
