Rounding Off — Definition

Definition

Rounding replaces a number with a nearby value at a specified place or precision. It simplifies communication and calculation but discards information. Under the common school convention for positive numbers, a following digit of five or more rounds the retained digit upward; other conventions must be followed when explicitly stated.

Estimation uses suitably rounded values to judge magnitude or compare options, while an exact calculation preserves the original inputs. A reliable solution states the precision, avoids premature repeated rounding and checks whether the possible rounding error could change the requested answer.