arithmetic
/əˈrɪθmətɪk; ə`rɪθməˌtɪk/ n[U]
(a) branch of mathematics that deals with calculations using numbers 算术.
(b) these calculations 算术的计算.
arithmetic / ˌærɪθˈmetɪk; ˌærɪθ`mɛtɪk/, arithmetical adjs of or concerning arithmetic 算术的; 关於算术的. ,arithmetic pro`gression (also arith,metical pro`gression) series of numbers that increase or decrease by the same amount each time, eg 1, 2, 3, etc or 8, 6, 4, etc 算数级数, 等差级数（如1, 2, 3等或8, 6, 4等）. Cf 参看 geometric progression (geometry).