Do students understand that a collection of centimeter cubes equal to the volume of a rock will displace an equal amount of water?
For evidence, observe students as they work, listen to their conversation with peers, ask questions, e.g., “Would you tell me about what you are doing?”
To interpret the evidence, ask yourself; Does this student:
- Begin with equal volumes of water?
- Compare the water level of the rock and cubes and note that when the water levels are equal, the number of cubes are equal to the volume of the rock?
- Count the number of cubes and describe the volume of the rock in cubic centimeters?
A possible next step would be to ask students to use props or drawings to describe what they did, why they did it, and what they found out.