at sixes and sevens

In disarray or confusion. The term comes from a game of dice in which throwing a six or seven has special significance, as it does in modern craps. There is considerable disagreement as to the precise game, or even if “six” or “seven” are not corruptions of sinque (five) and sice (six). Erasmus quoted a proverb to that effect, but, since dicing is very old indeed, the idea may be much older yet.