Ask your students to study the images shown below and draw conclusions about the density of the object they see sinking and/or floating in each set of pictures. Note that the same object is shown sinking in the first image and then floating in the second. The density slider indicates the density of the liquid in each image.

Example 1. Predict the density of the oval object in the figures below.



Liquid density = 1.6 g/cc.                Liquid density = 1.7 g/cc.



As another possible assessment strategy, have students make predictions about the density of three different liquids in your classroom such as vegetable oil, water and syrup. Students could then observe the arrangement of these liquids when they are combined in a density column. Ask students to explain the relative densities of these liquids based on their positions in the column. 

Additionally, you can have your students drop small objects in the liquids above and predict in which layer the objects will float, if at all.