This paper describes an integrated environment in which a student can acquire and test knowledge about Operations Research techniques. In this environment all the interactions with the users are performed by means of an appropriated graphical interface related to the problem and the algorithm chosen to solve it During a step-by-step problem solving session, the user makes the decisions and lets the system process the necessary computations. Moreover, this environment is able: (i) to check the correctness of the user's replies, (ii) to display warnings every time a wrong decision is taken, and (iii) to return to any previous step in order to give more flexibility to the teacher's exposition. The system is designed to include: Primal Simplex, Dual Simplex, Revised Simplex, Stepping-Stone Method for Transportation Problems, Hungarian Method for Assignment Problems, and Sensitivity Analysis