Arithmetic operators do what you think they do, that is, add, subtract, divide, and so on. It is something we are familiar with even without specific programming knowledge. Let's see each of them and how they can be used to manipulate the value of variables.

Before proceeding, keep in mind that for a shell script, a number is a decimal unless you prefix that with a 0 for the octal, a 0x for a hexadecimal number, or a base#number for a number that evaluates on the base.