The Chilean curriculum emphasizes problem-solving abilities together with other mathematical skills. However, it does not explicitly recognize problem posing, even though problem-posing abilities are central to the development of creative and critical thinking, essential in an Artificial-Intelligence-driven educational landscape. In particular, Chilean students face challenges in developing effective problem-solving abilities in all types of schools where teachers continue struggling to incorporate problem-solving strategies. This study investigates variations in problem-posing abilities among upper primary students across school types and grades in Chile. The research utilized three different problem-posing tasks involving different situations with a freestyle prompt, administered to students from public, private subsidized, and private schools. The findings reveal significant differences in problem-posing performance across school types and grades, with public schools exhibiting higher rates of challenges. Additionally, the study identified a trend of decreasing responses of nonrelevant or unsolvable problems as grade levels progressed; however, there was no overall linear pattern (increasing or decreasing) across grades. The findings contribute to our understanding of the dynamics of problem posing within the Chilean educational context. Recommendations are provided for curriculum designers and policymakers to bridge the gap between curriculum objectives and student challenges in problem posing. Moreover, the findings emphasize the importance of teacher development programs to prepare qualified teachers to support students’ problem-posing abilities.