Formative Assessment
Can students use evidence to reason that volume, not weight, determines how high the water level will rise?
Look for evidence in students’ notebook pages. As you interpret the notebook entries, remember that children typically think that heavier objects displace more water than lighter ones.
Does the student:
- Claim it’s volume and refer to evidence: (1) The aluminum and copper cubes had same volume and very different weights and water rose the same amount. (2) The two cubes with different volumes, made the water level rise different amounts.
- Claim it’s not weight and refer to evidence: (1) When the volumes were the same, the heavier cube did not make the water level rise more. (2) When the weights were the same but the volumes were different, the cube with the greater volume made the water level rise more.
As a next step, hold up a steel cube and a nylon cube and ask, “Which cube would make the water level rise more?”