Chemistry - the Complete Course Series, teaches students quantitative reasoning to solve chemistry problems. The 30 volume series covers all aspects of Chemistry from density to the mole, to molarity, stoichiometry and equilibrium. It demonstrates how to ask meaningful questions and conduct careful investigations to build knowledge of chemical and physical concepts and develop the skills to solve mathematical and scientific problems. Density is often the first quantitative concept studied in chemistry. To master the concept of density requires an understanding of the terms "mass" and "volume," and the units of g/cm 3. We can better learn the concept of density as well as develop a deeper understanding of what is involved in quantitative reasoning by working density problems. This volume teaches the disadvantages of using techniques such as proportion method or the factor-label method for finding density. That density is an excellent example of what is meant by a "ratio." How to understand what is meant by the quantities used in defining the density of something and how they are combined to produce the density unit.