Algebra - Operations

What is an operation?
In arithmetic we have different ways of working with numbers.
Examples of working with numbers are:
Addition     10 + 2 = 12
Subtraction    10 - 2 = 8
Multiplication    10 × 2 = 20
Division               10 ÷ 2 = 5

Addition, subtraction, multiplication and divsion are all examples of operations in arithmetic.
We also have the operations of addition, subtraction, multiplication and division in algebra.

In algebra, we do not just have numbers(constants) - we also have variables
so we have many possibilities including all of the following:
Variable + Constant    x + 2
Variable - Constant     x - 2
Constant × Variable    2 × x
Variable ÷ Constant    x ÷ 2
Variable + Variable     x + y
Variable - Variable     x - y
Variable × Variable     x × y
Variable ÷ Variable     x ÷ y