Meaning & use
do the math
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Meanings
phraseidiom
to work out the numbers or facts in order to understand what is really happening
Grammar: Used as an idiomatic verb phrase; it does not take an object, and it is often introduced by 'if you'.
Patterns
- if you do the math
- let's do the math
If you do the math, you'll see that renting is cheaper than buying right now.
She did the math and realized the company was losing money every month.
Do the math: three hours a day for a year is more than a thousand hours.
phraseidiom
used to tell someone that the facts are clear and they should accept the obvious conclusion
Grammar: Often used as a direct command to someone who is ignoring obvious facts.
Patterns
- do the math
- you do the math
He says he's not tired, but he's been awake for 20 hours — you do the math.
They keep spending more than they earn. Do the math.
Common combinations
- if you do the math
- If you do the math, you'll see the discount is tiny.
- do the math and see
- Do the math and see how much you'd save.
- you do the math
- She left at 6 and arrived at 9 — you do the math.
Synonyms and how they differ
- calculate
- This is a neutral verb for working with numbers; 'do the math' is more informal and often means understanding a situation, not just calculating.
- work it out
- This also means to find an answer by thinking, but it is broader and does not always involve numbers.
Commonly confused: do the math or do the maths?
do the math vs do the maths
This is the British English version of the same idiom. Use 'math' in American English and 'maths' in British English.
Practice
If you ___ the math, you'll see that the project will cost too much.
Choose one answer.
The idiom is 'do the math'. 'Make the math' is not used in this expression, and 'take' or 'get' do not fit the fixed phrase.
Make it your own
Write a sentence using “do the math”, then check it and compare it with the examples above.