It has recently became common that the authors of the physics textbooks describe, in general terms, the most importantsteps students have to follow in order to solve problems. The last step is usually a recommendation to “think about theresult” in order to find out if it is reasonable. Nevertheless, the standard formulation of exercises is such that “thinkingabout the result” is likely to be left out or, in the best scenario, it can be used only to fix students’ careless math errors.In fact, it seems that the physics textbook authors have on their minds precisely this role for the “thinking about theresult”. Even in the cases when the physical evaluation of the mathematically correct results is required explicitly, thestudents might not have the knowledge necessary to evaluate it in an appropriate way. In this article, a better way toformulate physics exercises is proposed. In such a formulation the evaluation of the result cannot be avoided.