数学概念教学（简称“概念教学”）在数学课堂中具有重要地位，做好概念教学对于能够帮助学生更好地了解数学、掌握数学。数学任务是课堂活动的主要载体和课堂结构的基本单位，选择恰当的任务和任务实施方式是概念教学实践的关键。调查表明，当前的课程改革注重学生的概念学习过程，但在实践层面许多教师还存在一些问题和困惑。因此，从数学任务视角研究概念教学改进过程对于教师优化教学具有重要的实践参考价值。

本研究依托某高校和中学合作开展的教学改进项目，以导数概念教学为例，在“授课教师独立备课（第一轮备课）——第一轮授课——集体备课（第二轮备课）——第二轮授课”的流程中探讨授课教师在概念教学任务设计与实施方面存在的问题及改进情况。研究采用课堂录像观察、文本编码分析等方法，收集上述流程中教师在各个环节的教学设计文稿或授课视频，从任务表现形式、“实际生活”背景知识、认知水平三个方面对其设计的数学任务进行分析，探讨教学改进前概念教学任务存在的问题和改进后数学任务的设计与实施情况。

研究发现：（1）教学改进前，概念教学任务设计与实施存在如下问题：任务设计方面，练习任务比重过大，高认知水平任务过多；任务实施方面，以课堂练习任务为教学重点，与纯数学任务相比实际生活类任务实施较为仓促，任务认知水平下降情况较多。（2）教学改进后，任务设计与实施情况如下：任务设计方面，概念学习任务成为重点，不同认知水平的任务比重更加合理；任务实施方面，课堂教学更加关注概念学习过程，实际生活类任务在课堂中得到更多的实施，任务认知水平保持较好。研究得到了一些有关概念教学任务设计与实施的建议：任务设计方面，以概念学习任务为核心，控制高认知水平的任务数量；任务实施方面，细化概念学习过程，注意挖掘实际生活类任务的情境价值，合理安排不同类型任务的课堂用时。

Mathematical concept teaching (referred to as "concept teaching") has an important position in the mathematics classroom, and good conceptual teaching is essential to help students better understand and master mathematics. Mathematics tasks are the main carrier of classroom activities and the basic unit of classroom structure, and the selection of appropriate tasks and task implementation is the key to classroom teaching practice. Surveys show that the current curriculum reform focuses on students' conceptual learning process, but many teachers still have some problems and confusions at the practical level. Therefore, exploring the conceptual teaching improvement process from the perspective of mathematical tasks has an important practical reference value for teachers to optimize teaching.

This study relies on a teaching improvement project carried out by a university and a secondary school, taking the teaching of the concept of derivatives as an example, exploring the problems and improvements in the design and implementation of the conceptual teaching tasks of the lecturers in the process of “independent preparation by the lecturers (first round of preparation) - first round of lectures - group preparation (second round of preparation) --In the process of “independent lesson preparation (first round of lesson preparation) - first round of teaching - group lesson preparation (second round of lesson preparation) - second round of teaching”, we explored the problems and improvements in the design and implementation of conceptual teaching tasks of the teaching staff. The study used classroom video observation, text coding analysis and other methods to collect teachers' instructional design manuscripts or videos of lectures in each section of the above process, analyze the mathematical tasks designed by the teachers in terms of task presentation forms, background knowledge of “real life”, and cognitive level, and explore the problems of conceptual instructional tasks before the improvement of teaching and learning, as well as the design and implementation of mathematical tasks after the improvement.

It was found that: (1) before the improvement of teaching, there were the following problems in the design and implementation of conceptual teaching tasks: in the design of tasks, too much weight was given to practice tasks, and too many high cognitive level tasks; in task implementation, classroom practice tasks were the focus of teaching, and the implementation of real-life tasks was more hasty compared with pure mathematics tasks, and there were many cases of decreasing cognitive levels of tasks. (2) After the teaching improvement, the task design and implementation were as follows: task design, concept learning tasks became the focus, and the proportion of tasks at different cognitive levels was more reasonable; task implementation, classroom teaching paid more attention to the concept learning process, real-life tasks were implemented more in the classroom, and the cognitive level of the task was maintained better. The study obtained some suggestions about the design and implementation of conceptual teaching tasks: in task design, the conceptual learning tasks should be the core, and the number of tasks at high cognitive levels should be controlled; in task implementation, the conceptual learning process should be refined, attention should be paid to mining the contextual value of real-life tasks, and the classroom time spent on different types of tasks should be reasonably arranged.