打小九九

打小九九

Literally means:

calculate and budget carefully and strictly

Actually means:

consider self-interest shrewdly

小九九, also jiujiu rhyme or jiujiu table, is the Chinese system of pithy formula of multiplication. Each formula renders a number with two numbers multiplied,from "one times one equals one" to "nine times nine equals eighty-one". This phrase means calculating and budgeting carefully and strictly. It also means shrewd consideration of selfinterest. In the latter sense the phrase is derogatory.

小九九，也叫九九歌或九九表，表中记载乘法的口诀，每个口诀给出每两个数相乘的得数，从“一 一得 一（一乘一等于一）”到“九九八十比喻在开支方面精打细算，也指暗中为自己打算（此时具有贬义）。