Students identify variables, constants, coefficients, and terms; translate between words and algebraic expressions; evaluate expressions with whole numbers, integers, fractions, and finite decimals using grouping symbols, whole-number exponents, and order of operations; and generate equivalent forms by combining like terms, applying properties, expanding, and factoring simple expressions. Students represent equations with balance models, tape diagrams, and one-step or simple multi-step contexts; write and solve addition, subtraction, multiplication, division, and fractional-coefficient equations; and check solutions by substitution while preserving equality. Students interpret, write, solve, and graph simple one-variable inequalities with whole numbers and familiar rational values, and use input-output tables, rules, ordered pairs, and coordinate graphs to describe dependent and independent variables and distinguish proportional from non-proportional patterns.