【教学内容】苏教版一年级数学下册第53、54页。【教材及学情分析】求减数的实际问题,就其数量关系来讲,仍然是过去学过的从总数里去掉一部分求另一部分,只是题中信息的呈现顺序与事情的发展顺序不一致。因此学生分析数量关系时会发生困难,而例题及习题中反映的数量之间的关系却是常见的数量关系。因此有必要帮助学生建立这种 【Teaching content】 First Edition of the Soviet version of the first volume of mathematics in the first 53,54 pages. 【Textbook and analysis of schooling】 The actual number of subtraction, in terms of the number of terms, is still in the past learned from the total number of parts removed for another part, but the question of the order of presentation of information inconsistent with the order of development of things. Therefore, students will encounter difficulties in analyzing the quantitative relationship, while the relationship between the examples and the quantities reflected in the exercises is a common quantitative relationship. It is therefore necessary to help students build this