Students identify variables, coefficients, constants, terms, and like terms, and translate between algebraic expressions and precise verbal descriptions involving sums, differences, products, quotients, grouping, and whole-number exponents. They evaluate expressions by substituting integer or rational values and applying order of operations, and recognize equivalent expressions using the commutative, associative, and distributive properties. They expand expressions with the distributive property, combine like terms, factor common numerical factors, and simplify multi-step expressions containing parentheses, variables, constants, and integer or rational coefficients.