The minus symbol is used in math to represent the subtraction operator. Note, this character is different from the hyphen symbol found on the keyboard. Typically, the symbol is used in an expression like this:
In plain language, this expression represents the number six minus the number five.
Subtraction is a basic arithmetic operation of taking away one number from another number.
The minus symbol is used in set theory to represent the difference operator for two sets. The operation removes all elements found in one set from another and returns the resulting set.