Arithmetic

Arithmetic or arithmetics (from the Greek word ἀριθμός, arithmos "number") is the oldest^[1] and most elementary branch of mathematics (compared to algebra, geometry, and analysis).

It consists in the study of numbers, especially the properties of the traditional operations between them — addition, subtraction, multiplication and division.

Arithmetic is an elementary part of number theory. However the terms arithmetic and higher arithmetic were used until the beginning of 20th century as synonyms for number theory, and are, sometimes, still used to refer to a wider part of number theory.^[2]