arithmetic

Từ điển Oxford Advanced Learner 8th

arith·met·ic BrE [əˈrɪθmətɪk] NAmE [əˈrɪθmətɪk] noun uncountable
1. the type of mathematics that deals with the adding, multiplying, etc. of numbers
•He's not very good at arithmetic.
2. sums involving the adding, multiplying, etc. of numbers
•a quick bit of mental arithmetic (= sums you do in your head, without writing anything down)
•I think there's something wrong with your arithmetic.

Word Origin:
[arithmetic] Middle English: from Old French arismetique, based on Latin arithmetica, from Greek arithmētikē (tekhnē) ‘(art) of counting’, from arithmos ‘number’.

Example Bank:
•I've worked out the price, but I need to check the arithmetic.
•a test of mental arithmetic