The Principle of Least Action, as formulated by Pierre Louis Moreau de Maupertuis (1698–1759), is historically placed in those decades, between the end of the 17th century and the first half of the 18th century, which saw the birth and development of calculus of variations, a privileged mathematical tool for the study of physical phenomena relating, among others, to the classical mechanics and geometrical optics. The presentation of the Principle of Least Action as a natural generalization of Fermat's Principle allows us to appreciate the evolution of mathematical tools for extremality conditions. The Principle of Least Action can be though in different proposals, depending on the high school courses, as well as on the mathematical tools held by the students. A first idea concerns the mathematical formalization of physical phenomena reproducible in the laboratory (even with limited equipment) such as the refraction of light and perfectly inelastic collision in one dimension; the second proposal, which could also be aimed at grammar schools, will focus on the historical and epistemological aspects of the Principle of Least Action in its various formulations.