/əˈrɪθmətɪk ||; əˈrɪθməˌtɪk/noun
[U] (mathematics数学) the kind of mathematics which involves counting with numbers (adding, subtracting, multiplying and dividing) 算术:
I'm not very good at mental arithmetic.我不大善于心算。
arithmeticnoun (no plural)(maths) working with numbers, for example by adding or multiplying, to find the answer to a sum: I'm not very good at mental arithmetic.