《义务教育数学课程标准》明确指出:“培养学生的计算能力,要重视学生基本的口算训练,引导学生在理解的基础上掌握基本的口算方法,坚持经常训练,逐步达到熟练。”在整个小学阶段,口算既是笔算、估算和简便计算的基础,也是计算能力的重要组成部分。事实上,任何一道计算题都是由若干道口算题综合组成的。口算能力差,势必会影响到估算、笔算的正确和速度,影响计算技能的形式。在小学低年级,学生在校60%左右的数学学习时间都 “Compulsory Education Mathematics Curriculum Standard” clearly states: “To cultivate students ’computing abilities, we should attach importance to students’ basic training in oral arithmetic and guide students to master basic oral arithmetic based on understanding, adhere to regular training, and gradually achieve proficiency.” Throughout the entire primary school, counting is not only the basis for calculating, estimating and facilitating calculations, but also an important component of computing power. In fact, any calculation problem is composed of a number of crossroads. Mouth arithmetic ability is bound to affect the estimation, the accuracy and speed of pen calculations, the form of computing skills. In the lower primary school, students spend about 60% of their math study time