How we express a number depends on whether we are a computer or a human. If we are human, we are likely to express numbers using our familiar 10-base decimal system. If we are a computer, we are likely, at our core, to express numbers as 2-base or binary.
This is a companion discussion topic for the original entry at https://linuxconfig.org/computer-math-basics-binary-decimal-hexadecimal-octal