九年义务教育教材初中代数第一册第一章“代数初步知识”开门见山地引进“代数式”的概念,这体现了初中代数与小学数学最主要的区别.小学数学主要学习数的运算,而初中代数除了进一步扩充数的范围外,还要研究式的运算以及和式有密切关 The nine-year compulsory education teaching materials for junior high school algebra, the first chapter of the first chapter of the “algebraic preliminary knowledge” openly introduced the concept of “algebraic”, which reflects the main difference between junior high school algebra and primary school mathematics. Primary school mathematics mainly to learn the number of operations, and junior high school Algebra, in addition to further expansion of the number of the range, but also the study of the formula and the equation is closely related