Identify, create, extend, and describe repeating and growing patterns using objects, shapes, numbers, tables, hundreds charts, and simple additive rules, including odd-even patterns and changes of 10 within familiar whole-number ranges through 1,000. Determine and apply consistent one-step input-output rules involving addition, subtraction, and familiar equal-group contexts, completing missing inputs or outputs without variables or complex formulas. Recognize equality and use symbols to solve, balance, and write addition and subtraction equations and story equations with whole numbers within 100, including unknowns in any position and reasoning with inverse operations.