The right answer is letters
Arithmetic is a branch of mathematics that studies the numbers and the properties with them. The main properties are addition, subtraction, multiplication and division. Variables are non-constant values, so we use letters to assign a number to a variable and the operator that allows us to do this is =. For instance, if we have the variable x, we can say that this variable is equal to 4. Then:
Suppose the value of the variable changes to 5, then the new value of it is given by:
