What does "at sixes and sevens" mean?

Confused, disorganized, disorderly, as in We've just moved in, and the office is still at sixes and sevens, or The new college admissions tests were poorly explained, leaving the students at sixes and sevens. This ancient term is thought to come from a game of dice in which throwing a six or seven had a particular significance. The name of the game has been lost, but most likely betting on such a throw was very risky, denoting disorder and confusion. [Late 1300s]