At the end of the XIXth century, some mathematicians like Charles-Ange Laisant (1841-1920) or Édouard Lucas (1842-1891) develop new ideas about teaching mathematics using innovative tools or original visualizations. These ideas are linked to their interest for recreational games viewed through a mathematical background and other specific problems from combinatory, number theory, algorithms and the « géométrie de situation ». We propose to give some examples of these mathematical representations and these ingenious games, explicitly presented by their authors in a didactical scheme. Moreover, many of these approaches could be presented nowadays to students of secondary schools. We discuss the role of visualizations through these experimentations and we point out the connections between diagrams and symbolisms. We study the need of arousing curiosity through striking results. We also underline the goals of representing processes in certain moments of mathematical learning and the benefits of these presentations, much more than simple recreational questions.