Lesson Summary In this lesson, students observe what happens to the water level when objects are submerged.  By submerging objects in a graduated cylinder and observing that the water level rises, students are introduced to displacement. Furthermore, students use the cylinders from the object bag to explore how objects of different weight, but of equal volume, displace the same amount of water. Students learn that displacement is directly related to the volume of the objects, not to its weight. Teacher Background Whenever an object is placed in a liquid, it pushes aside (or displaces) the liquid. Some students may have difficulty understanding that, although the cylinders have different weight and materials, they displace exactly the same amount of liquid because the volume is the same.  However, the wood cylinder will displace a smaller amount of liquid because it floats. This may lead to a good discussion about the connection between the amount of an object that is below the surface of the water, displacement, and buoyant force. Set-up/Management Tips Ahead of time, cut masking tape strips to the height of graduated cylinder. Separate clay into smaller sections (enough for a student pair to mold a cylinder). Pull the cylinders from the object bags. If water has been saved in containers, it can be reused for this investigation. Set up multiple testing stations. Literacy Support Scientific Vocabulary The following words are key vocabulary words that will be introduced in this lesson and reinforced throughout the unit: Submerge Graduated Cylinder Centimeters as a measurement