Unit 1 Prototype: Rate of Change-Linear Functions through a Covariational Lens

Note on Iterative Development: The Unit 1 Prototype, Instructor Guide, Pretest/Posttest, Analytic Codes, and Assessment Rubrics (v0.5) hosted here reflect substantial revisions following a pilot implementation of the initial curriculum (v0.1) in Fall 2025. While preliminary pilot results provide evidence of promise, the current prototype expands and re-sequences tasks—most notably shifting from instructor-led GeoGebra demonstrations to student-controlled exploratory activities—to more explicitly elicit interiorized reasoning, including rate as a multiplicative operator and rate-as-object actions (comparison, additive combination, and reversal) identified as key areas for refinement during the pilot.