Assess early learners' ability to analyze and explain why objects sink or float by comparing material, shape, and size. Students will predict outcomes, perform simple water tests with paired objects (same material/different shape or different material/same shape), record observations, and give age-appropriate explanations using comparative language (e.g., heavier/lighter, hollow/solid, more/less dense). Focus on evidence-based reasoning for Pre-K–Grade 2 rather than formal calculations.