This study investigates pedagogical content knowledge (PCK) among teachers teaching mathematics at the preschool level in Colombia, highlighting the importance of integrating mathematical knowledge with innovative and effective pedagogical strategies. Using a mixed exploratory and transactional methodology, the perceptions and practices of 82 teachers were examined, focusing on their understanding of mathematical content, pedagogical skills, and knowledge of children’s cognitive development. The findings reveal a significant gap in teachers’ understanding of these concepts, indicating a critical need to strengthen PCK among teachers. To this end, training should be provided to enable teachers to foster meaningful and contextualized mathematical learning in preschool students. The study suggests reviewing teacher training curricula and fostering the development of pedagogical strategies that prioritize conceptual understanding and mathematical reasoning. Additionally, it identifies critical areas for improvement and offers concrete recommendations for transforming mathematics teaching in preschool education. To enhance the quality of mathematics education, several measures are proposed: ensuring continued availability of training programs for teachers, encouraging collaboration between educators, adopting constructivist approaches, and helping teachers understand the value of mathematics learning outside the school.

With the continuous development of education, the double reduction policy has gradually become the focus of educators. Especially for junior high school mathematics classrooms, there is an indelible connection between whether students can learn mathematics well and whether classroom teaching is effective, and the effectiveness of the classroom is often related to factors such as students' stress level. Therefore, as a qualified junior high school mathematics teacher, it is necessary to carefully do pre class work in daily teaching and research practice, design different forms of teaching and research plans under the double reduction policy, establish a unique learning atmosphere for students, and improve their core mathematical qualities. This article proposes corresponding solutions and strategies on how to carry out mathematics classroom teaching under the double reduction policy.

The six core competencies of mathematics in vocational schools are becoming increasingly important in mathematics learning. The reverse teaching design of vocational school mathematics, which focuses on core competencies, precisely grasps the internal logic of knowledge from a holistic perspective, and designs it on a unit by unit basis. The design process is to infer the starting point from the endpoint. Therefore, how to use reverse thinking in teaching design research in vocational school mathematics teaching under the background of core competencies will be the main content of this article.