Solving problems by different methods, identifying the knowledge put at stake in each case, and stating variants of the problems are fundamental aspects of the competence of analysis of mathematical knowledge for teaching. This paper reports on the design, implementation, and results of a formative intervention with primary education prospective teachers to promote developing this competence using tasks that involve proportional and algebraic reasoning. The experience has been carried out with a sample of 88 students (two class-groups), applying a didactic model that includes work in teams, institutionalization, and assessment of the individual learning achieved. Seventy three percent of students were successful in solving problems; however, only 27% of students managed to solve the four problems proposed by at least two different procedures. More than half of the students adequately identified the knowledge involved in each problem and the algebraization level was correctly assigned in more than half of the proposed solutions. Elaborating meaningful variants to the problems was only achieved in a suitable way by less than 20% of the students. It is concluded that developing the epistemic analysis competence of tasks bringing into play proportional and algebraic reasoning requires a greater attention in the teachers’ formative programs.

通过不同的方法解决问题，识别每种情况下所涉及的知识以及陈述问题的变体是用于教学的数学知识分析能力的基本方面。本文报告了与初等教育准教师进行的形成性干预的设计，实施和结果，目的是通过使用涉及比例和代数推理的任务来促进这种能力的发展。该经验是由88名学生（两个班级）的样本进行的，采用了包括团队合作，制度化和对所获得的个人学习进行评估的教学模型。73％的学生成功解决了问题；但是，只有27％的学生设法解决了至少两个不同程序提出的四个问题。超过一半的学生充分识别了每个问题所涉及的知识，并且超过一半的拟议解决方案正确分配了代数化水平。只有不到20％的学生以适当的方式为问题精心设计了有意义的变体。结论是，发展任务的认知分析能力以发挥比例和代数推理的作用，需要在教师的形成程序中给予更多的关注。