Definition
Approximation
An approximation is a value close to the exact value and suitable for a particular purpose.
Continue from this idea into connected AXIO math.
Boundary check: 7.9 ≈ 8.0, but 7.9 ≠ 8.0.
What it means
Sometimes an exact value is unknown, unnecessary, or awkward to use. You choose a nearby value that makes the task manageable, then state its accuracy when that matters. Rounding, estimating, and measuring can all produce approximations.
Remember it
Close enough for the job—not exactly equal.
Example
A route is 3.82 km long. Saying it is about 3.8 km is an approximation to the nearest tenth of a kilometre. It is useful for describing the route, but 3.8 km is not exactly 3.82 km.
Watch for
A number chosen with no reason or accuracy goal is only a guess, not a justified approximation.
Common mix-up
Estimation is a process for finding a rough value; the value you use or report is an approximation.
Exact meaning
An approximation is a value used in place of an exact value because it is sufficiently close for the stated purpose or required accuracy.