[ shī zhī háo lí，chà zhī qiān lǐ ]

指细微的失误，可导致巨大的差错。

《大戴礼记·保傅》：“《易》曰：‘正其本，万物理。失之毫厘，差之千里。’故君子慎重始也。”

a tiny lapse can lead to a huge mistake (idiom); a minor discrepancy leading to enormous losses