【故事一】教学模式的缺失——经验主义数学老师A在借鉴他人、总结自身教学经验的基础上,形成了“设疑激趣——提出问题——学生探究并回答问题——课堂练习”的教学结构。这种教学结构的实质是基于问题的教学。在其执教北师版四年级上册第五单元“商不变的规律”一课时,她进行了如下设计和教学:第一环节,设疑激趣。(出示三组题)(30×5)÷(10×5)=?(30÷2)÷(10÷2)=?(30×2)÷(10×2)=?(30÷10)÷(10÷10)=? 【Story One】 Lack of Teaching Mode - Empirical Mathematics Teacher A, based on his own experiences and lessons learned from others, has formed a “doubt-provoking question-asking questions-students exploring and answering questions-class exercises ”Teaching structure. The essence of this teaching structure is problem-based teaching. In its coaching the fourth edition of the Beijing Normal University unit fifth unit “business the same rules ” a class, she conducted the following design and teaching: the first part, set suspicion. (30 x 2) ÷ (10 x 2) =? (30 ÷ 10) = (30 ÷ 2) ÷ (10 ÷ 2) ÷ (10 ÷ 2) ÷ (10 ÷ 10) =?