- Add 250 ml (1 cup) of gravel to the bottom of your plastic container. Smooth it out so it's flat on top.
- Place the coffee filter on the gravel. Pour 125 ml (1/2 cup) of sand in the filter without spilling it on the layer of gravel.
- On the next page, write your prediction about what will happen to the water when you add it to your model.
- Use the eyedropper to add drops of water to your model. Stop after using about half of the water in the small cup.
- Observe where the water goes and how it moves. Record your observations on the next page.
- Use the eyedropper to add the rest of the water to your model.
- Place the model in a safe location where it will not be disturbed until your final observations.