Meaning & use
approximation
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Meanings
nouncountable
A number, amount or description that is close to the true one but not exact.
Grammar: Countable: a rough approximation, or two approximations of the same figure.
Patterns
- an approximation of something
- a rough approximation
Three point one four is only an approximation of pi.
The guide gave us a rough approximation of how long the climb would take.
My budget is just an approximation, because prices change.
nouncountable
Something that is similar to another thing but is not quite the same, often a weaker copy.
Grammar: Often followed by of: an approximation of the real thing.
Patterns
- an approximation of something
The cafe served a sad approximation of a French croissant.
Her accent was a fair approximation of a Texan drawl.
The model is a decent approximation of the original building.
noununcountablemathematics
The process of finding a value or result that is close enough to the correct one, used in mathematics and science.
Grammar: Usually uncountable here: errors arise in approximation.
Patterns
- approximation by something
- approximation of a function
Approximation is useful when an exact solution is too hard to calculate.
The engineers used numerical approximation to solve the equation.
Her thesis is on the approximation of curves by straight lines.
Word forms
| plural | approximations |
|---|
Common combinations
- rough approximation
- A rough approximation will do for the first estimate.
- close approximation
- The painting is a close approximation of the original.
- reasonable approximation
- Fifty is a reasonable approximation of the crowd size.
- crude approximation
- His map was a crude approximation of the coastline.
- first approximation
- As a first approximation, assume the road is straight.
- in approximation
- The numbers were given in approximation, not as exact counts.
Synonyms and how they differ
- estimate
- An estimate is a judgment of an amount made on purpose, while an approximation can also be a result near the true value found by calculation.
- guess
- A guess is informal and may rest on little information, whereas an approximation suggests some reasoning behind the closeness.
- ballpark figure
- A ballpark figure is a casual, spoken way to give a rough number, whereas approximation fits writing and technical work.
- likeness
- Likeness refers to resemblance in appearance, not to numbers, and it is more positive than a weak approximation.
Opposites
Word family
- approximate adjective
- close to the exact figure but not perfectly accurate
- approximate verb
- to come close to a value or to be nearly the same as something
- approximately adverb
- about, not exactly
- approximative adjective
- giving a result that is roughly right; a rare technical word
Commonly confused: approximation or estimation? approximation or proximity?
approximation vs estimation
Estimation is the act of working out a rough amount, while an approximation is the result or the near-copy itself.
approximation vs proximity
Proximity means nearness in space or time; approximation means nearness in value or likeness.
Practice
The recipe card said 'about two cups of flour.' What is that figure?
Choose one answer.
About two cups is a close but not exact amount, so it is an approximation. An exact measurement would give a precise number, and nothing suggests a mistake.
Make it your own
Write a sentence using “approximation”, then check it and compare it with the examples above.