The widespread availability of generative artificial intelligence tools poses new challenges for school mathematics education, particularly regarding the formative role of traditional mathematical tasks. In post-AI educational contexts, many activities can be solved automatically, without engaging students in interpretation, decision-making, or mathematical validation processes. This study analyzes a secondary school classroom experience in which open mathematical tasks are implemented as a didactic response to this scenario, aiming to sustain students' mathematical activity. Adopting a qualitative and descriptive-interpretative approach, the study examines the forms of mathematical work that emerge during task resolution, mediated by the didactic regulation device COMPAS. The analysis is structured around four analytical axes: open task design in post-AI contexts, students' mathematical agency, human-AI complementarity, and modeling and validation practices. The findings suggest that, under explicit didactic regulation, students retain epistemic control over mathematical activity, even in the presence of generative artificial intelligence.

翻译：生成式人工智能工具的广泛普及为学校数学教育带来了新的挑战，尤其是在传统数学任务的育人功能方面。在后AI教育语境中，许多教学活动可被自动完成，而无需学生参与解释、决策或数学验证过程。本研究分析了一项在中学课堂中实施开放数学任务作为应对此情境的教学实践，旨在维持学生的数学活动参与。研究采用质性描述-解释方法，考察了在COMPAS教学调控机制中介下任务解决过程中涌现的数学工作形态。分析围绕四个核心维度展开：后AI语境下的开放任务设计、学生数学主体性、人机互补性以及建模与验证实践。研究结果表明，在明确的教学调控下，即使存在生成式人工智能，学生仍能保持对数学活动的认知控制权。