With the outbreak of the pandemic in the world we often hear about "exponential growth", "Rt factor", "peak of contagions": all these concepts, used in Medicine, are typical of Mathematics, which has become one of the most fashionable disciplines in recent times. Often, in fact, mathematical concepts are used, sometimes in informal contexts and sometimes the speakers are not fully aware of the meaning of the terms they use and of the theories underlying them. For this reason we believe that it is important for students to learn in a critical and scientifically correct way which mathematical theories underlie the choices of governments, which are often not understood by the population that often does not follow the indications adequately.