The process of approximating a quantity, usually done for convenience or, in the case of numerical computations, of necessity. If rounding is performed on each of a series of numbers in a long computation, round-off errors can become important, especially if division by a small number ever occurs.
See also Shadowing Theorem
References
Wilkinson, J. H. Rounding Errors in Algebraic Processes. New York: Dover, 1994.