Knowledge and skills:

(1) A preliminary understanding of the meaning of the equation will determine whether a formula is an equation.

(2) The quantitative relationship will be expressed by equations as required.

Process and method:

Experience the process of understanding equations and the learning method of observation and comparison.

Emotional attitudes and values:

In learning activities, stimulate students' interest in learning, cultivate students' ability to use their hands and brains, and develop serious and good study habits.

Emphasis and difficulty in teaching

Teaching focus:

In order to understand the meaning of the equation, we will use the equation to express the equivalence relation in a simple case.

Teaching difficulties:

Correctly analyze the quantitative relationship in the topic

teaching tool

Multimedia equipment

teaching process

Teaching process design

1 Create scenarios and reveal topics.

(1) shows the balance of the body.

Teacher: Do you know each other? What role does it play in life? (Weigh the object to balance the left and right)

(2) Demonstration: Show three weights with the mass of 20g, 30g and 50g respectively (with the unlabeled side facing the students).

Teacher: We don't know their weight yet. What happens if you put the scales in two plates? Students observe and find that the balance is balanced (at this time, the side marked with weight faces the students).

Question: Can an equation be used to express the mass relationship between objects on both sides of the balance? (Students write in their notebooks and answer by name. )

Writing on the blackboard: the meaning of equation

2 New knowledge exploration

(A show examples of teaching materials (see PPT courseware)

Explanation: An equation with an equal sign is called an equation, which means that the results on both sides of the equal sign are equal.

(blackboard writing: an equation with an equal sign is called an equation)

[Design Intention]: Let students experience the equation in a balanced and intuitive situation, which is in line with students' cognitive characteristics. Let the students use equations to express the equal relationship between the masses of objects on both sides of the balance and understand the meaning of the equations.

(2) Guide classification and summarize the concept of equation.

1, students learn by themselves (see PPT courseware)

Requirements:

(1) Students fill in the form by themselves, and express the mass relationship on both sides of the balance with formulas.

(2) Divide students into groups to exchange eight formulas, and finally reach a unified understanding:

20+30 = 50 20+X = 100 50+X = 100 50+2X & gt； 100 80 & lt； 2X 3X = 150 100+20 & gt； 100+50 100+2X >50? According to the students' answers, the teacher writes these eight formulas on the blackboard. )

(3) Divide these eight formulas into two categories, how to divide them, think independently before group communication, and give reasons. A, think about what is your classification standard? Write down your classification on paper?

Students may divide it like this:

The first type: equal belongs to one category, and unequal belongs to one category.

(20+30 = 50 20+X = 100 50+X = 100 3X = 150)(50+2X & gt； 100 80 & lt； 2X 100+20 & gt； 100+50 100+2X >50? 3)

The second type: with and without unknowns.

(20+X = 100 50+X = 100 50+2X & gt； 100 80 & lt； 2X 3X = 150 100+2X & gt； 50? 3)(20+30 = 50 100+20 >； 100+50)

2. Comparative analysis and summary of concepts.

Transition: It seems that students can classify formulas according to their own standards. Guide students to understand the first method: why do you want to divide it like this? Speak your mind.

A, the teacher pointed to the blackboard and said: The formula on the right is the equation we are going to learn today. (blackboard writing: an equation like X+ 100=250, so _ _ _ _ _ _ _ _)

Can you tell me what an equation is?

C, students speak, to sum up: like 20+x =100,3? = 180 So, an equation with unknowns is called an equation?

Teacher (blackboard writing)

Teacher's question: Which two words do you think are more important in this sentence?

Health:? Equations with unknowns?

Teacher: That X+ 100 > 100, x+50 <; Why is 100 not an equation?

Health: Because they are not equations,

The teacher asked: What is the relationship between equation and equation? Communicate in healthy groups.

An equation must be an equation, but an equation is not necessarily an equation.

Teacher: ⅹ=0, ⅹ=a, ⅹ=a2 are equations?

Health: Yes, because they contain both unknowns and equations.

3. Give examples of equations and understand concepts. Can you give an example of the equation? Can someone lift something different from what just happened? (A complex equation represented by the letter Y)

Student enumeration: ⅹ+5 =186 (ⅹ-2) = 246 (ⅹ-2) = 245 ⅹ = 30 ⅹ? 4=6 ⅹ+ⅹ+ⅹ+ⅹ=35

(ⅹ+4)? 2 = 3 x+y = 5 and so on.

Teacher: Now do students know what the relationship between equations is?

Health: the equation must be an equation, but the equation is not necessarily an equation.

Teacher: Can you express the relationship between equations in your own way?

Report on healthy thinking.

3 Consolidation and promotion

1、? Try it?

(1) Observe the balance diagram on the left, talk about the quantitative relationship in the diagram, and list the equations.

(2) Observe the picture on the right, find out the meaning of the problem and list the equations.

2. practice.

Judge whether the following statement is correct.

(1) equations are all equations, but they are not necessarily equations. ( ? )

(2) An equation with an unknown number is called an equation. ( ? )

(3) The solution of the equation and the solution of the equation are the same thing. ( ? )

(4)X2 cannot be equal to 2X. ( ? )

(5) 10=4X-8 is not an equation. ( ? )

(6) Equations are all equations. ( ? )

3. Exercise 1

1, such as 100+x=250 (unknown) is called an equation.

2. Discuss and judge: Which of the following equations are equations and which are not?

8x = 06x+24+2 & gt； 10

2y？ 5 = 10n-5m = 15 17-8 = 9

10 & lt； 3m 6x+3 = 1 1+2x 4+3z = 10

Is the equation: 8x=0 2y? 5 = 10n-5m = 156x+3 = 1 1+2x 4+3z = 10

What is not an equation is: 6x+24+2 >; 10 17-8 = 9 10 & lt； 3m

4. Exercise 2

1, relation: An equation with an unknown number is called an equation, so what is the relationship between the equation and the equation? Can you express the relationship between equations in your own way?

2. Use equations to express the quantitative relationship in the following practical problems.

(1) Xiaohong bought a bag of 50 kg of rice, ate 3 kg, and left 30 kg. (3x+30=50)

(2) Zhao Hua's home is 240 meters away from school. She walks from home to school for 3 minutes and walks 60 meters every minute. (60 x 3x=240)

(3) Xiaoming is X years old and his father is 40 years old. The difference between them is 28 years old. (28+x=40)

(4) Xiao Fang runs skm every day and 28km a week (7s = 28).

(5) There is one piece in a can of candy, which is distributed to 25 children on average, and each child gets 3 pieces, which is exactly the end point. (a？ 25=3)

Summary after class

In this lesson, I learned what an equation is: an equation with unknown numbers is called an equation. I also learned the relationship between equality and equation: an equation must be an equation, but an equation is not necessarily an equation.

Write on the blackboard.

Meaning of equation

Concept of equality: An equality with an equal sign is called an equality.

The concept of equation:? An equation with unknowns is called an equation?

Judging whether the formula is a condition that the equation must meet;

( 1)? Including unknowns?

(2)? Equation?

note:

An equation must be an equation, but an equation is not necessarily an equation.

The Meaning of Equation Teaching Plan (2) Teaching Objectives

Knowledge goal: understand and master the meaning of equation, and make clear the relationship between Chu equation and equation.

Ability goal: to cultivate students' ability to observe, think and analyze problems seriously.

Emotional goal: to stimulate students' interest and cultivate cooperative consciousness through independent inquiry, cooperative communication and other teaching activities.

Emphasis and difficulty in teaching

Teaching emphasis: understand and master the meaning of equation.

Teaching difficulties: find out the similarities and differences between equations and equations.

teaching tool

courseware

teaching process

First, the new lesson introduces the courseware to show the balance, so that students can talk about the characteristics of the balance. The teacher summed up the balance of the scales.

Teacher: How can we make the left and right sides of the balance equal? Show me a balance. There are 20 grams and 30 grams of objects on the left and 50 grams on the right.

Teacher: How to express it by formula?

Health: 20+30=50 leads to this equation.

Second, explore the new lesson, and then show that the left side of the balance is 20 grams of objects and? G object, and on the right is 100 g object. Teacher:? What does this mean? What can we say? Health: It is indicated by letters. Student 1: 20+X = 100 student 2: 100-X = 20 student 3: 100-20 = X teacher: which formula do you think can better represent the balance on both sides of the balance? It is concluded that 20+x= 100 indicates the balance between the left and right sides of the balance. Show six scales and write the formula according to the balance state of the scales. Put these eight formulas in order and get the exercises: ① 20+30 = 50 ⑤ 80.

Equality and inequality

①20+30=50 ④50+2? & gt 180 ②20+? = 100⑤80 & lt； 2? ③50? 2 = 100⑦ 100+20 & lt； 100+50 ⑥ 3? = 180 ⑧ 100+2? =3? 50

Formulas with unknowns, formulas without unknowns.

②20+? = 100 ①20+30=50 ④50+2? & gt 180 ③50? 2 = 100⑤80 & lt； 2? ⑦ 100+20 & lt； 100+50 ⑥ 3? = 180 ⑧ 100+2? =3? 50

Teacher: What formulas are both equations and unknowns?

Health: ②20+? = 100 ⑥ 3? = 180 ⑧ 100+2? =3? 50

Equations with unknowns like this have a new name today, called. Equation? Write on the blackboard and practice the equation: which of the following are equations? Which are not equations? ①5-? = 12 ( ) ② y+24 ( ) ③ 5？ +32 = 47()④28 & lt； 16+ 15()⑤6(a+2)= 42()⑥0.48 = 6()⑦35+65 = 100()⑧？ -2 1 & gt； 72 ( ) ⑨ 9b-3=60 ( ) ⑩？ +y=60 degrees ()

Can you write some equations yourself? Please perform on the blackboard, and the other students will write in their exercise books. )

Teacher: Have you got a better understanding of the equation through this lesson? Cong Cong also listed two formulas, which were accidentally stained with ink. Guess if he listed the equation at the beginning? ( 1) 6? +() =78 (2) 36+() =42 Student feedback

Show courseware:? The equation must be an equation, and the equation must also be an equation? Is this sentence correct? Discuss with each other in the group and draw a conclusion and report it to the teacher for collective correction. Can you express the relationship between equations in your own way? The equation must be an equation; But the equation is not necessarily an equation.

Third, the class summed up what did you gain from this lesson?

Fourth, the homework is completed. Page 63? Do it. 1 and 2 questions.