Which system includes both fractional and whole numbers in calculation?

The decimal system is the most widely used number system in everyday life and includes both fractional and whole numbers. In this system, numbers are represented using ten digits (0-9), which allows for the representation of whole numbers (like 1, 2, 3) as well as fractions (like 0.5, 1.75, etc.) using a decimal point. This versatility makes it suitable for precise calculations in mathematics, finance, and science.

The other systems mentioned, such as binary, octal, and hexadecimal, have specific uses primarily in computing and digital electronics. The binary system, for example, uses only two digits (0 and 1) and primarily represents whole numbers. The octal system, based on eight digits (0-7), and the hexadecimal system, which consists of sixteen symbols (0-9 and A-F), follow similar conventions and are less commonly used for fractional numbers outside of their respective applications. Thus, the decimal system is distinguished by its straightforward inclusion of both whole numbers and fractions, making it the correct answer in this context.