Students often fail to formulate phenomenon when they are solving dynamics problems. In the case of conventional ITS, their failures are tried to remedy in terms of dynamical concepts and formulas. However, the remediations are not always effective, because they often can't understand the errors including in their formulas. To correct the errors effectively, it is required to help them to recognize the errors. Generally, human is more sensitive to contravention of constraints in real world than in formula world. From this point of view, we propose a framework of "Fake Simulation" which can simulate the phenomenon reflecting to the errors including in the formulas. The students can recognize contravention of constraints in motion easier than that in formulas. Fake Simulation is one of visualization method of errors, which enables them to understand their errors and to correct the errors. Furthermore, it can prevent them recurring. We have already implemented Fake Simulation for dynamics. We also report the results of preliminary experiment for evaluating Fake Simulation.