Assess students' ability to decompose whole numbers up to 10 into two-part number bonds. Tasks include finding missing addends, listing all possible pairs for a given whole, representing decompositions with objects, pictures, or equations, and explaining/analyzing strategies (e.g., commutativity, complements to 10). Emphasize reasoning: ask students to compare decompositions, justify choices, and apply understanding to moderate problems within the 0–10 range.