Definition
Algebra
Algebra uses symbols and structure to describe quantities, relationships, patterns, and general rules.
What it means
Algebra lets one rule stand for many number cases. A letter can name a number you do not know yet, a number that can change, or any number in a general pattern. You then use valid mathematical moves to evaluate, compare, or solve.
Remember it
Algebra turns a number relationship into a rule you can work with.
Example
Let n be the number of stickers in one pack. Four packs contain 4n stickers. If 4n = 28, divide both sides by 4 to find n = 7.
Watch for
A page is not algebra just because it contains a letter; the symbol must represent a quantity, relationship, or general mathematical rule.
Common mix-up
A variable is one tool used in algebra. Algebra is the wider study of the structures and relationships built with those tools.
Exact meaning
Algebra studies quantities and the rules relating them, often using symbols to form and transform expressions, equations, inequalities, functions, and general statements while preserving their meaning.