Measuring the volume of liquids and solids is a skill that takes precision and therefore takes practice. To give students more opportunity to practice, we completed a Measuring Volume Gizmo today. In the virtual lab students used beakers, graduated cylinders, and pipettes to transfer water, and then used a magnifying glass to zoom in on the meniscus and read the volume.
There are two modes in the Measuring Volume Gizmo, Free Explore and Practice. In the Free Explore mode, students simply practice the skill of transferring water from one container into another and reading the volume in mL. However, in the Practice mode students are tested on their measuring skills and given immediate feedback on their precision.
By the end of the task, students felt more comfortable reading the volume of a liquid in a graduated cylinder, and were better able to measure the volume of a solid using water displacement.
Here is one example of a task that students should be able to complete by the end of their exploration. Fill a graduated cylinder with 20 mL of water, then place a rock in the graduated cylinder. What is the volume of the rock?
(Hint: To answer correctly, be sure that you are reading from the bottom of the meniscus.)
After the rock is placed in the graduated cylinder, the water displaces from 20 mL to 35 mL, therefore the volume of the rock, or the amount of space the rock takes up, is 15 mL.