Assess students' ability to design a self-sustaining classroom terrarium (mini-ecosystem) that balances plants, the water cycle, soil layers, and decomposers. Tasks: produce a simple labeled drawing or plan selecting plants and soil, describe how water moves and recycles inside the terrarium, explain the role of decomposers in returning nutrients, predict observable signs of balance or imbalance, and propose one maintenance/troubleshooting action. Intended for Pre-K–Grade 2 with adult scaffolding; emphasizes cause–effect, cycles, and creative problem solving.