Its all about the divisors.
base 10 <--metric system: Divisors are 1, 2, 5 and 10
base 12 <--much of the imperial system: Divisors are 1, 2, 3, 4, 6, and 12.
By having 6 divisors instead of 4 a party can divide a whole into equal parts among a larger number of individuals.
This explanation...