At sixes and sevens
Disorder Seven Eight Messy
So in China seven and eight is more messy than sixes and sevens? Well, isn't it nice with some idioms and chengyus that lend themselves to numbers? Did some wise folks run out of words, since they had to start using numbers?
Anyway, here is a good chengyu, should be fairly easy to remember. Enjoy using it - it should prompt some smiles.