The definition of algebraic expression in the book is: an expression formed by connecting numbers and letters with operational symbols (addition, subtraction, multiplication, division, multiplication, root, etc.). ) is called an algebraic expression. Simply put, mathematics (or arithmetic) in primary school involves more letters, and the scope and rules of operation are correspondingly broadened; Of course, for the sake of unity and convenience, we also call formulas without letters algebraic formulas.

People's education edition books are available online. I'll give you a website /czsx/jszx/qnjsc/7akb/

Algebraic expressions involve many chapters. In junior high school, we are exposed to algebraic expressions, fractions and quadratic roots. In the People's Education Edition,

The second chapter of the first volume of grade one is the addition and subtraction of algebraic expressions.

Chapter 15 of the first volume of the second day of junior high school is multiplication, division and factorization of algebraic expressions.

Chapter 16 of the second volume of the second day of junior high school talks about fractions.

Chapter 2 1 of the first volume of the third grade is about quadratic roots.

I am a junior high school teacher, but I use the experimental textbook of Zhejiang Education Edition. There is no electronic textbook.

I hope it helps you.