In this contribution, we show the practical use of the computer to visualise simple computational simulations to show phenomena that occur in everyday life, or require an abstract understanding for being unintuitive phenomena. The relationship of the mathematics to different scientific disciplines motivates us to devise different treatments to find a solution for understanding and predicting what happens in nature. In this way, other scientific areas call for new mathematics and these in turn provide new discoveries. Today there are several computational tools to develop learning units that enable allow understanding of different concepts. One is the Python language, which contains tools for numerical and symbolic calculations, and also for graphical visualisations with the advantage of being open and easy to learn. Currently, the Jupyter project is an environment in which different languages come together under one programming scheme. In this manuscript, we show how we have adapted IPython Notebook to show some simulations on some phenomena related to geometric problems, numerical calculation and its applications in mechanical and electromagnetic systems. In this way, the authors have designed a web site containing learning units based on examples of mathematical, physical and biological problems.