Algebraic Expression
Numbers, symbols and operators (such as + and ×) grouped together that show the value of something.
Variable
A symbol for a value we don’t know yet. It is usually a letter like x or y.
Constant
a number on its own, or sometimes a letter such as a, b or c to stand for a fixed number
Equivalent Expressions
expressions with the same value
Factor
Numbers we can multiply together to get another number.