Thermodynamics education is not easy both for students and teachers. But the Entropy, Chemical potential, Real gas structure, Fugacity, Molecular interaction, Supercritical phenomena chapters become more comprehensible, if introduced via the pure real gases' cluster physics chapter. A pure gas consists of the only one type of basic particles, therefore, the molar Gibbs energy G is universal for all basic particles. The monomer fraction Gibbs energy Gm logarithmically depends on the monomer fraction density, Dm, which is a perfect argument for thermophysical properties series expansions, named canonical for their correspondence to the fundamental Mass action law. Unlike virial expansions, the n-th canonical expansion coefficient reflects properties of the n-particle cluster. The canonical expansion of various thermodynamics functions, for which precise experimental data may be taken from the NIST Webbook, opens the clusters vision from different points of view. The potential energy of a gas provides the clusters' bond parameters cognition. The bond energy temperature dependence discovers different cluster isomers and the directional bonding. The near critical cluster fractions structure reflects the gas-to-liquid soft structural transition. For students it is useful to develop the canonical series expansion and the cluster structure analysis skills. [For the full proceedings, see ED623149.]