三下五除二

three, set five remove two (abacus rule) / efficiently / quickly and easily

three / 3

down / downwards / below / lower / later / next (week etc) / second (of two parts) / to decline / to go down / to arrive at (a decision, conclusion etc) / measure word to show the frequency of an action

five / 5

to get rid of / to remove / to exclude / to eliminate / to wipe out / to divide / except / not including

two / 2 / (Beijing dialect) stupid