七年级数学第二章“有理数的加法与减法”这一节知识中,有理数省略加号的加减混合运算,这部分内容确实是有理数加减混合运算的一个难点和关键点,对于后继学习有理数的综合运算、整式的加减运算都起到非常关键的作用.但受知识、经验和方法的局限,学生在运算的过程中难免会产生错解.这些 In the second chapter of the seventh grade mathematics, “the addition and subtraction of rational numbers”, rational addition and subtraction of rational numbers to the plus and minus mixed operations, this part is really a difficult point and key point of rational addition and subtraction, for the successor Learning rational numbers of the integrated computing, the whole addition and subtraction operations play a very crucial role, but by the limitations of knowledge, experience and methods, students will inevitably have errors in the operation process.