The theory of modelling uses differential sind integral equations and numerical approximations of their solution for simulation of various chemical and biochemical processes. We find mathematical analogy frequently between different fields of natural sciences i.e. physics, chemistry or biology. If the mathematical analogy is obvious, a fascinating question is to investigate its deeper reasons. For evaluation we need not only theoretical work but also the best tools of information technology. In our paper we show examples from the field of biological and chemical growth models and physical chemistry. A new idea to find a good mathematical model is discussed as well.