Assess learners' ability to select, apply, and justify the most efficient strategy for comparing and adding small quantities (0–20). Tasks require choosing between approaches (number bonds, make‑ten, count‑on, grouping tens/ones), representing reasoning with models or equations, comparing alternative methods, and explaining why one method is more efficient (fewer steps, mental ease, place‑value insight). Include items that ask students to identify and correct less efficient or erroneous strategies. Appropriate for Pre‑K–Grade 2 with an evaluate-level cognitive demand.