Students' productive struggle in mathematics is described as the rigorous learning which can effectively promote grit and creative problem solving. This study aimed to determine and communicate students' perceptions on the struggle they experienced in their Calculus class, how this affects their learning and what mathematical tasks teachers need to develop to enhance students' level of achievement and creativity in Calculus. Survey questionnaires were handed to both engineering and mathematics education students and an experimental study was conducted during the first semester of school year 2016-17. In the analysis, students noted that they struggle because they need it for the program they are enrolled while others showed deeper understanding on how they can be productive after the effortful learning experiences. Further, the result of the experimental study showed that the problem-based Hawaii Algebra Learning Project (HALP) model problem solving and the pre-withinpost solution problem-posing activities revealed a positive effect on students' achievement and enhanced the level of students' mathematical creativity in terms of fluency, flexibility, and originality of their solutions in the Multiple Solutions Tasks (MST) test. Future researchers may consider utilizing these methods and exploring other strategies which could highly impact students' achievement level and creative ability in mathematics.