教学内容苏教版四年级下册“用字母表示数”教前分析本课是学生代数学习的起始课,是后续学习代数式、方程、不等式、函数的重要基础。教材对这部分知识已作了一些前期孕伏,在教学加法和乘法的运算律及长方形、正方形的周长、面积计算公式时,都曾引导学生用字母来表示。从具体的数过渡到用字母表示数,是学生数学认知的一次飞跃,是由数 Teaching content Sujiao version of the fourth grade under the book “with the number of letters ” pre-teaching analysis This lesson is the beginning of the students algebraic learning class, follow-up study of algebraic equations, equations, inequality, an important basis for the function. The textbook has made some pre-pregnancy on this part of the knowledge. When teaching arithmetic of addition and multiplication of teaching, and rectangle, square perimeter and area calculation formula, students are all guided by the letters. From a specific number of transitions to the number of letters, is a leap in student cognitive mathematics, is composed of a few