4. Mineral Materials:  Investigation 4.2

How can we measure the volumes of rocks?

2. Estimate and measure the volume of rocks

Small Groups 15 Mins Notebook
Rock and cube replica in water

Distribute a tray of materials to each group. Explain that each pair of students will estimate and then measure the volume of one of the rocks on the tray; they will then combine their data with the data for the second rock collected by the other pair.

Students estimate the volume of their rock. They first build a rock replica using centimeter cubes. Students record their estimates in their notebooks specifying the unit of measurement (cubic centimeters) each time [Which rock has more volume?].

Students then check their estimates using the water displacement procedure devised by the class, recording the procedure and results in their notebooks.

Steps for Measuring the Volumes of the Rocks: 

  1. Equalize the starting water levels and mark them on the containers.
  2. Place the rock in one container and mark the new water level after the water has been displaced.
  3. Add centimeter cubes to the second container, one at a time, counting as you go, until the water level matches the water level in the first container. The number of cubes is the measured volume.