a·rith·me·tic 
(ə-rĭthmĭ-tĭk)
(ə-rĭthmĭ-tĭk)n.
The mathematics of integers, rational numbers, real numbers, or complex numbers under addition, subtraction, multiplication, and division.
adj. ar·ith·met·ic (ăr′ĭth-mĕtĭk) also ar′ith·meti·cal (ăr′ĭth-mĕtĭ-kəl)
1. Of or relating to arithmetic.
2. Changing according to an arithmetic progression: The increase in the food supply is arithmetic.
[Middle English arsmetike, from Old French arismetique, from Medieval Latin arismetica, alteration of Latin arithmētica, from Greek arithmētikē (tekhnē), (art) of counting, feminine of arithmētikos, from arithmein, to count, from arithmos, number; see ar- in the Appendix of Indo-European roots.]
ar′ith·meti·cal·ly adv.
a·rith′me·tician (-tĭshən) n.
- restore
- restorer
- restrain
- restrainable
- restrained
- restrainedly
- restrainer
- restraining order
- restraint
- restraint of trade
- restrict
- restricted
- restrictedly
- restricter
- restriction
- restriction enzyme
- restrictionism
- restrictionist
- restrictive
- restrictively
- restrictiveness
- restrictor
- restrike
- restroom
- restructure