一、问题的提出笔者在一年级数学教学以及调研中常常发现,一年级新入学儿童的加减法口算能力很不平衡。有的学生在学前就已经经历了几年的加减法计算练习,有的学生不仅10以内加减法能熟练计算,甚至20以内、100以内加减法也会计算,同时也还有不少学生20以内加减法 First, the issue put forward In my first grade mathematics teaching and research I often found that first-year newcomers children’s ability to add and subtract is very unbalanced. Some students in pre-school experience has gone through several years of addition and subtraction calculation exercises, and some students not only can be less than 10 addition and subtraction can be proficient, even less than 20, 100 addition and subtraction will be calculated, but also a lot of Addition and subtraction within 20 students