Aim for damp
Moisture levels two or three support model decomposition.
Compost Crew
Supply green and brown materials, moisture and air to step a compost model.
Grades 2–5 · Biology
Your goal
Make at least 2 model compost units. Supply green and brown materials, moisture level 2 or 3, and air level 2 or more.
Reduced motion is on. The controls still update the scene.
4 green units, 8 brown units and 0 compost units total 12. The mixture is too dry.
A fresh recipe has 8 brown units. Changing it restarts decomposition.
Decomposers such as bacteria and fungi break down dead materials. Greens and browns contribute different nutrients and structure. The model converts one unit of each into two compost bookkeeping tokens per suitable step and uses one air level. These units are not a real mixing ratio, time forecast or sealed mass balance. Real compost exchanges water and gases with its surroundings.
Related resources
Related simulations
Learn with Compost Crew
Compost Crew invites elementary students to investigate the conditions decomposers need. Choose a fresh mixture of green and brown material tokens, adjust moisture, and turn the bin to add air. Advance decomposition steps to convert paired material tokens into model compost while watching the air level fall. Dry, waterlogged or poorly aerated conditions stop progress in this simplified comparison. A visible count keeps twelve bookkeeping units accounted for throughout each recipe. The activity distinguishes its token rules from real compost ratios, decomposition times and the exchange of gases and water with the environment.
What to look for
Add air
Turn the bin when the air level becomes low.
Compare fresh mixtures
Changing the recipe restarts the same twelve-token sample.
For teachers and curious learners
Identify conditions that support decomposer activity and track illustrative materials. Ask students to predict what will happen, change one setting, and explain what they observe. Learn gives a starting point. Practice and Challenge offer new goals with the same scene.
Paired token conversion conserves twelve illustrative units, not real mass in an open compost bin. Counts, air use and steps do not predict mixing ratios or elapsed time.