【教学内容】苏教版一年级下第74页和第84页。两位数的加减法是一年级下册的重点学习内容,教材编排充分体现循序渐进、螺旋上升的原则,十分注重旧知与新知、基础与发展的逻辑关联。以《两位数加法(进位)》为例,学生已经具备的知识基础上有“两位数加一位数不进位”、“两位数加两位数不进位”、“20以内的进位加法”等,新知学习也分为“两位数加一位数(进位)”、“两位数加两位数(进位)”两个内容分两个课时来完成。按照这样的编排,教学中要注意循序渐进、拾级而 Teaching content】 【Sujiao first grade under the 74th and 84th pages. The double-digit addition and subtraction method is the key learning content for the first grade and the second volume. The textbook arrangement fully embodies the principle of gradual and orderly spiral and attaches great importance to the logical relationship between old knowledge and new knowledge, foundations and development. To “two-digit addition (carry)” as an example, students already have the knowledge on the basis of “two digits plus one digit does not carry”, “two digits plus two digits not carry”, “Addition of additions within 20” and so on, the new learning is also divided into “two digits plus one digit (carry) ”, "two digits plus two digits (carry) Class time to complete. In accordance with such a choreography, teaching should pay attention to gradual and orderly