Variables and expressions
Use symbols to name numbers or quantities, describe their allowed values, and evaluate expressions by replacing every occurrence consistently. Preserve grouping, signs, fractions and units, and distinguish a calculated value from solving an equation or proving two rules equivalent.
Key knowledge
A variable is a symbol representing a value in a specified domain. An algebraic expression combines numbers, variables and operations; substituting permitted values evaluates the expression.
Conditions and scope
- Specify the domain and any exclusions, such as a nonzero denominator.
- An expression alone does not assert equality or inequality.
Sources · 8
References
Sources retain their recorded scope. A source link alone does not establish verification of every statement.
- TIMES · Algebraic expressionsAustralian Mathematical Sciences InstituteTeaching resource
National Council of Educational Research and Training (NCERT)2 sources
- Mastery Professional Development · 1.4 Simplifying and manipulating expressions, equations and formulaeNational Centre for Excellence in the Teaching of Mathematics (NCETM)Teaching resource · PDF
- TIMES · Algebraic expressionsAMSI and University of Melbourne, ICE-EMTeaching resource
Evidence and review
Variable, expression and substitution terminology.
2026-10-10 · Checked the distinction between an expression and an equation.
Foundational review
2026-10-10 · Fresh primary-source inspection of the complete compact record, including every statement, equation, quantity and material condition, followed by independent AI editorial review. This check does not certify all linked lessons or every passage of every cited publication.
Sources from other places
Scope or convention differs
Symbols and permitted substitution evaluate algebraic expressions.
Introductory examples restrict their number domain; repository exclusions apply more generally.
Australian Mathematical Sciences Institute and University of Melbourne
- TIMES · Algebraic expressions AustraliaEnglish
Using pronumerals; Evaluating algebraic expressions
- TIMES · Algebraic expressions
Related articles
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