For developing web-based resources for an undergraduate course in Numerical Methods, four computational systems (Maple®, Mathcad®, Mathematica®, and Matlab®) were used to illustrate algorithms, convergence, and pitfalls of different numerical methods. In this paper, we discuss the advantages and drawbacks of each mathematical package based on this experience. Also as an example, from the four computational systems, we show the source code and output for one of the simulations.