Formative Assessment

Do students understand that when the weights of oil and water are equal, the oil will always occupy more space?

Listen for evidence of understanding as the class discusses their findings. How would you interpret this student’s statement?

• Will the volume of the oil always be greater?
• What is her claim?
• What evidence does she use to back up her claim?

A next step might be a question, “What if we had 30 grams of oil and 30 grams of water, how would the volumes compare? Explain the reasons for your answer.”