📦 Mystery Containers Build-and-Battle

Teams rotate through a fast challenge using mystery containers, solid models, rice or cubes for filling, rulers, and a shared recording sheet. They predict which solid fits the same space with the least wasted surface area, test one comparison, and record measurements, observations, and one efficiency claim tied to the local storage or floor-plan brief. Midway through, teams use a quick partner protocol with another team to name one strength and one revision for the solid choice, then make a second model attempt and close with a brief circle share naming one math decision and one teamwork move.