Content and content analysis:

"Square difference formula" is a special form of polynomial multiplication after students master the knowledge of rational number operation, simple algebraic expressions, linear equations and inequalities, addition and subtraction of algebraic expressions, multiplication of algebraic expressions and so on.

It is a typical example of cognitive law from general to special. The study and research on it not only gives a simple algorithm of special polynomial multiplication, but also lays a foundation for factorization, fractional simplification, quadratic root denominator rationalization, solving quadratic equations and functions in one variable, and also provides a method for learning complete square formula. Therefore, the square difference formula is also very important in junior high school teaching, and it is the first one in junior high school.

The teaching emphasis of "square difference formula" is to experience and explore the whole process of square difference formula, and to use the formula for simple operation.

Objectives and objective analysis:

Goal:

1, through the exploration process of square difference formula, further develop students' sense of symbol, reasoning ability and inductive ability;

2. Master the structural characteristics of the square difference formula and be able to use the formula for simple operations;

3. I will explain the meaning of the formula with geometric figures and experience the thinking method of combining numbers and shapes.

Target resolution:

1, let students experience the process of "special case-induction-conjecture-verification-representation with mathematical symbols", accumulate experience in mathematical activities, further develop students' sense of symbols, reasoning ability and inductive ability, appreciate the concise beauty of mathematics, cultivate their reasonable reasoning and inductive ability, and the importance of cooperation and communication with others in the process of solving problems.

2. Let students know the background of the square difference formula, understand its meaning, master its structural characteristics, and use it flexibly to solve problems. In mathematics activities, students are guided to observe and analyze its structural characteristics and the broad meanings of letters in the formula, and the mistakes in practice are analyzed in detail to deepen their understanding of the formula.

3. Through independent inquiry and cooperative communication, let students experience the process of exploring, consolidating and expanding new knowledge, give full play to students' main role, and enhance students' interest in learning and using mathematics. At the same time, let students accumulate experience in solving problems in the use of formulas and experience the joy of success.