Definition of do the maths in English:

do the maths

phrase

British
informal
  • often in imperative Make a calculation or come to a conclusion based on the relevant facts and figures, typically with the implication that the result is or should be obvious.

    ‘I have four children and one on the way; you do the maths’
    • ‘I'll leave you to do the maths on that one, and to work out for yourself whether 10% is a "rapid" rate of depreciation.’
    • ‘Your cut-price carrier ticket is around a third of the price of the full fare—do the maths.’
    • ‘Just do the maths: most people I know will be really out of pocket, by several thousand dollars a year.’
    • ‘This year's expected yield of 10,000 pounds of plums is enough to feed—well, you do the maths.’
    • ‘When I finally got back to Victoria it was quarter past eight, we were supposed to be due in at half five. You do the maths!’