Simplest form: An expression is in simplest form when it is easiest to use. (e.g. Combined like terms)     

Reciprocal: To get the reciprocal of a number, we divide 1 by the number. (e.g. the reciprocal of 2 is 1/2) 

Expression: Numbers, symbols and operators (such as + and x) grouped together that show the value of something.

Equation: An equation says that two things are equal. It will have an equal sign =.

Formula: A formula is a mathematical rule or relationship that uses letters to represent amounts which can be changed. 

Identity: An identity is an equation which is always true, no matter what values are substituted. 

Inequality: An inequality compares two values, showing if one is less than, greater than, or simply not equal to another value. 

Term: In algebra a term is either a single number or variable, or numbers and variables multiplied together. 

Factor: Numbers we can multiply together to get another number.

Expand: Expand is when we multiply to remove the bracket. 

Factorise: Finding what to multiply to get an expression.