numerical analysis

from The American Heritage® Dictionary of the English Language, 5th Edition.

• noun The study of approximation techniques for solving mathematical problems, taking into account the extent of possible errors.

from Wiktionary, Creative Commons Attribution/Share-Alike License.

• noun mathematics The study of algorithms to solve mathematical problems concerning continuous sets of values (such as the real numbers, complex numbers or vector spaces).

from WordNet 3.0 Copyright 2006 by Princeton University. All rights reserved.

• noun (mathematics) the branch of mathematics that studies algorithms for approximating solutions to problems in the infinitesimal calculus