For decades, chemistry educators have assumed that practice makes perfect—that repeated exposure to chemical calculation problems inevitably builds competence. Yet, recent international evidence paints a more troubling picture: students routinely fail even basic calculation tasks despite years of instruction, and often feel confident while doing so. This symposium invites researchers to examine why chemical calculations persistently challenge learners across educational levels, whether due to conceptual weaknesses (mole concept, stoichiometry, mass conservation), symbolic manipulation difficulties, reading comprehension demands, representational transitions, or cognitive load. The contributions included in the symposium address conceptual, linguistic, representational, or cognitive barriers, cross-representational fluency, the role of task design and verbal load, students’ metacognition, and interventions that improve performance beyond increased practice. By putting chemistry calculations under the microscope, this symposium seeks to challenge long-held assumptions, reveal hidden mechanisms of student difficulty, and advance innovative research that moves the field forward.
