The noun is pronounced /ərɪθmɪtɪk/. The adjective is pronounced /ærɪθmetɪk/.
1.
Arithmetic is the part of mathematics that is concerned with the addition, subtraction, multiplication, and division of numbers.
...an arithmetic test.
N-UNCOUNT
2.
You can use arithmetic to refer to the process of doing a particular sum or calculation.
4,000 women put in ten rupees each, which if my arithmetic is right adds up to 40,000 rupees.
N-UNCOUNT : oft poss N
3.
If you refer to the arithmetic of a situation, you are concerned with those aspects of it that can be expressed in numbers, and how they affect the situation.
The budgetary arithmetic suggests that government borrowing is set to surge...
N-UNCOUNT : usu the N
4.
Arithmetic means relating to or consisting of calculations involving numbers.
...a processor which performs simple arithmetic operations such as adding or multiplying numbers.
ADJ : ADJ n