Assess young learners' ability to apply principles of shape, size, weight, and balance to design a stable block tower. Tasks include selecting and arranging block shapes and sizes to create a wide, supportive base, predicting how center-of-gravity and stacking order affect stability, testing towers under gentle disturbances, and explaining design choices with simple observations and evidence. Materials and constraints (limited blocks, uneven pieces) increase challenge for Pre-K–Grade 2 learners while focusing on application and reasoning.