Translation guide
The ability to perform calculations in one's head without external aids. In Japanese, this is commonly referred to as 暗算 (あんざん), but other expressions exist for different contexts.
The act of calculating in one's head, without pen, paper, or calculator.
The standard term for mental arithmetic. Used in everyday conversation and educational settings.
He is good at mental arithmetic.
Please calculate it mentally.
Literally 'calculate in one's head'. A more descriptive phrase, often used when explaining the process.
It's difficult to calculate in my head.
Verb form of 暗算. Used to say 'do mental arithmetic'.
Try doing it mentally without a calculator.
A specific method of mental arithmetic using an imaginary abacus, often taught in Japanese schools.
Shortcuts or tricks for doing mental arithmetic quickly.
Tips or tricks for mental arithmetic.
Please teach me some mental arithmetic tricks.
暗算 is the most natural and common way to say 'mental arithmetic'. It can be used as a noun or with する to form a verb. In casual conversation, you might hear 暗算で (by mental arithmetic) as an adverbial phrase.
Abacus-based mental arithmetic improves concentration.