Key learning points

1. A single number or letter, or the product of numbers and/or variables.
2. An expression contains one or more terms, where each term is separated by an operator.
3. An equation is a statement that two expressions are equal, indicated by =
4. An identity is an equation which is always true, regardless of the values substituted in.
5. A formula is a mathematical rule or relationship connecting two or more variables.

Keywords

• Term - A term is single number or letter, or the product of numbers and/or variables. Each term is separated by the operators + and –

• Expression - Expressions contain one or more terms, where each term is separated by an operator.

• Equation - An equation is used to show 2 expressions that are equal to each other.

• Identity - An identity is an equation that holds true for all values of the variables. The symbol ≡ is used to show two expressions are equivalent and form an identity.

• Formula - A formula is a rule linking sets of physical variables in context.

Common misconception