失之毫厘,謬以千里 [ㄕ ㄓ ㄏㄠˊ ㄌㄧˊ , ㄇㄧㄡˋ ㄧˇ ㄑㄧㄢ ㄌㄧˇ; shi1 zhi1 hao2 li2 , miu4 yi3 qian1 li3] a tiny lapse can lead to a huge mistake (idiom); a minor discrepancy leading to enormous losses ◄ ►