價格：免費
檔案大小：22.7 MB
版本需求：需要 iOS 9.3 或以上版本。與 iPhone、iPad 及 iPod touch 相容。
支援語言：英語
Mental calculation comprises arithmetical calculations using only the human brain, with no help from calculators, computers, or pen and paper. People use mental calculation when computing tools are not available, when it is faster than other means of calculation (for example, conventional methods as taught in educational institutions), or in a competitive context. Mental calculation often involves the use of specific techniques devised for specific types of problems.
支援平台：iPhone