XCalc Calculator app for iPhone and iPad

The modern electronic calculator is a handheld electronic machine that can perform mathematical calculations. It has integrated circuit chips, but its structure is much simpler than that of computers. It can be said that it is the first generation of electronic computers (computers), and its functions are also weak, but it is more convenient and cheap. It can be widely used in commercial transactions, and it is one of the necessary office supplies. In addition to displaying the calculation results, there are also overflow indications and error indications.