Create Density Layers with 16%, 12%, 8%, 4% and 0% sucrose in water, colored with food dyes, by adding each successively less dense layer in a graduated cylinder. Use a pipet, and prevent mixing of layers by delivering solution into a deflagrating spoon held on the surface of the layer below to stop downward inertia of solution.
Layered, colored sucrose solutions of different concentrations
Density Demonstrations Using Diet Soft Drinks 
Mass and Density-A Surprising Classroom Demonstration