“钉子板上的多边形”是苏教版五年级《数学》的教学内容,教学这一课时,余荣军老师使学生在探索规律、发现规律和表达规律的过程中,进一步感受数学抽象的意义,培养比较、分析和简单推理的能力,增强发现问题、提出问题的意识,积累数学活动经验。下面笔者撷取三个教学片段与同仁共赏。【片段一】激趣生疑,引发猜想师:你能在钉子板上围一围多边形吗?要求每人围3 “Polygon on nail plate ” is the teaching content of the fifth grade “mathematics” of the Sujiao edition. When teaching this lesson, Yu Rongjun teacher makes the students further experience the mathematical abstraction in the process of exploring the law, discovering the law and expressing the law Significance, ability to cultivate comparisons, analyzes and simple reasoning, enhance the discovery of problems, raise the awareness of problems and accumulate experience in mathematical activities. The following author captured three teaching fragments and peer rewards. [Fragment one] interesting suspicious, trigger guess Teacher: Can you enclose a polygon around the nail plate?