do the math
Compute the answer
Do the math means to calculate or figure something out, often with the implication that the conclusion is obvious once you consider the facts: She's been gone for two hours and the store is ten minutes away—do the math.
The phrase frequently carries a note of exasperation, suggesting the listener should have already reached the obvious conclusion.
In British English, the phrase is do the maths.
figure out
Determine through reasoning
determine · assess · evaluate · analyze · put two and two together · realize · understand · reckon · gauge · surmise
compute
Determine by calculation
total · crunch numbers · multiply · divide · subtract · figure · calculate · equation · arithmetic · formula
- math expressionsadd up, crunch numbers, number crunching, number cruncher, factor in
do the mathwing it
Act without preparation
shoot from the hip · play it by ear · guesstimate · guess · follow your heart
does, done, doer, doers, undone, the, math, maths, mathematics