價格：免費
檔案大小：24.1 MB
版本需求：需要 iOS 10.0 或以上版本。與 iPhone、iPad 及 iPod touch 相容。
支援語言：英語
Romans used a rather peculiar numeral system that is represented by latin letters rather than numbers. R2A helps you convert numbers, and allows to test your knowledge of Roman numerals making it a little easier to learn this historically significant numeral system.
支援平台：iPhone, iPad