Teaching Design of Addition and Subtraction of Algebraic Expressions 1 Teacher: Students, do you remember the definitions of similar terms and merged similar terms?
Health: I can basically answer completely.
Teacher: (writing on the blackboard)
Is it correct to combine the following questions with similar projects? If not, please correct it.
( 1)2 ax2+3 ax2 = 5ax 4；
(2)6x+2y = 8xy；
(3)8 x2-3 x2 = 5；
(4)9a2b-9ba2=0。
Student: Answer orally.
Teacher: Give an evaluation.
Teachers: guide students to solve problems in two ways: direct substitution evaluation method; Merge similar items first, and then substitute them for evaluation.
Health: Let's count the first small problem in your seat.
Teacher: Patrol and guide students to solve problems in two ways (1).
Teachers and students: The teacher analyzes the questions and writes two complete answering processes on the blackboard according to the results of students' oral answers.
Health: I realize the position of the rule of merging similar items in the operation.
Teacher: Ask two students to write two kinds of problem-solving processes on the blackboard and realize the benefits of merging similar items again.
Teachers and students: evaluate the results together.
Student: Students look at problems together and then think independently. Students write important information in class exercise books.
Teacher: Patrol the students to answer questions and give them the necessary information. In particular, encourage students with weak foundations to eliminate their fear of application problems.
Teacher: Guide students to use positive and negative numbers to represent quantities with opposite meanings, and then list the formulas. The remaining work is to simplify the formula by combining similar terms.
Student: Students answer the listed formulas and calculation results orally.
Teacher: Remind students not to lose the negative sign of the first item when merging similar items.
Teacher: Emphasize the problem-solving format.
Teacher: Ask two students to play the problem-solving process on the blackboard, and the other students write it in the classroom exercise book.
Student: Look at the problem together, and then think independently.
Teacher: Comment on the students' performance process. Re-emphasize the importance of format.
Teacher: It is emphasized that when merging similar items, the sign of the second item is negative when the coefficients are added.
Teachers and students: Applause for two students.
Teacher: Try it! Which student volunteered to answer these two questions?
Student: Some students raised their hands and actively participated in classroom activities.
Student: Two students are performing on the blackboard.
Teachers and students: evaluate students' problem-solving process together.
Teacher: Emphasize the flexible use of knowledge, especially in the process of solving the second question.
Teacher: Man struggles upwards! Now let's challenge this "mountain" together! Think independently for two minutes, and then discuss in groups.
Student: Think independently first. Several students can finish the problem in two minutes.
Student: After two minutes, students can discuss freely for one minute, and then continue to solve the problem or check whether the answer just now is wrong.
Teachers and students: share the discussion results and give encouragement to the outstanding ones.
Teacher: Analyze the meaning of the problem and write the whole problem-solving process on the blackboard completely. Cultivate students' ability to solve problems in a standardized way.
Teachers and students share the harvest of this lesson.
Instructional design of algebraic expressions of addition and subtraction (2) Teaching objectives;
Analysis of teaching content:
The teaching content of this lesson is algebraic addition and subtraction (lesson 65438 +0), which is a lesson after learning algebraic related concepts. Algebraic addition and subtraction operation is the basis of algebraic operation, factorization, solving quadratic equations and functions, and it is a formal transition from "number" to "formula", which has a very important position. The knowledge base of algebraic addition and subtraction operation is the concept and merging of similar items, and algebraic addition and subtraction operation mainly simplifies algebra by merging similar items, so the position of this lesson in middle school mathematics is self-evident.
Teaching emphases and difficulties:
The concept of similar items and the method of merging similar items
Instructional design concept:
For a long time, students' awareness of active learning is weak and they are highly dependent on teachers. Students are in a state of passive acceptance for a long time, which makes them introverted, passive, lack of self-confidence and obedient ... which stifles their creativity. The new curriculum requires "changing the current situation that the implementation of the curriculum places too much emphasis on learning, rote memorization and mechanical training, advocating students' active participation, willingness to explore and diligent hands-on, and cultivating students' abilities of collecting and processing information, acquiring new knowledge, analyzing and solving problems, and communicating and cooperating". Therefore, our teachers are required to change "imparting knowledge" into "educational exchange" and "tutoring" into "learning courses", provide students with opportunities to engage in mathematics activities in the classroom, help students change the old learning model, guide students to explore and solve problems independently in learning activities, and make every student gain something in the mathematics classroom. In order to highlight the teaching focus and break through the teaching difficulties, this class plans to adopt inquiry teaching method: by observing life examples, starting from students' existing life experience, adopting cooperative inquiry learning mode, and carrying out learning activities through group cooperative discussion, students can independently discover, analyze and solve problems, gain successful experience in the inquiry process, enhance their confidence in learning mathematics, develop their enthusiasm for learning mathematics, and let them experience in the inquiry activities.
Main teaching process design:
Reflection after teaching:
The teaching design of this course is based on students' inquiry learning mode, which aims to make students know mathematics, understand and master basic mathematical knowledge, basic mathematical skills and basic mathematical methods in the atmosphere of independent exploration, personal practice and cooperation and exchange, and fully embody the concept of the new curriculum.
First, success
This lesson emphasizes three "points":
(A) focus on creating problem situations. At the beginning of class, students are classified in kind to stimulate their interest in learning and quickly adjust their attention and thinking activities to a positive state. Then, let the students classify the same type of monomials through observation, draw out the concept of similar items, and analyze the concept of similar items through "games", which can fully reveal the' connotation' of the concept of similar items and provide students with opportunities to fully engage in mathematical activities. In particular, [Activity 8] asks "How many people are there after three people plus five people?" This easy-to-understand question, and then further put forward "three people plus five tables make eight people?" Or eight tables? "This seemingly absurd problem actually breaks through the key and difficult point of merging similar items, that is, adding the coefficients of similar items, the result is taken as the coefficient, and the index of letters remains unchanged; When merging similar items, only similar items can be merged into one item, not similar items cannot be merged.
(2) Pay attention to the cooperation and communication between students. Students' mathematics learning activities should be a lively, proactive and personalized process, and hands-on practice, independent exploration and cooperative communication are important methods for students to learn mathematics. In the process of designing this class, we pay great attention to this aspect of activity design, from the classification of objects, the introduction of concepts to the analysis of concepts and the summary of the class, which embodies the new curriculum concept that students are the masters of learning everywhere.
(3) Pay attention to the cultivation of ability. In the teaching design of this course, we pay attention to students' hands-on, mouth-opening and brain-thinking, which develops students' learning enthusiasm, not only trains students' language expression ability, but also cultivates students' abilities of independent exploration, independent learning, cooperative communication, cooperative learning and induction, develops students' divergent thinking, cultivates students' flexibility and rigor of thinking, cultivates students' exploration spirit and innovative personality, improves students' ability to process information and exercises students' practical ability.
Second, the need for improvement
Depending on the actual situation of students, it would be icing on the cake if students could practice the textbook to 165 pages, such as 1, and then the teacher would comment on it. Because students have mastered the concept of similar items and the method of merging similar items, they can better understand that "mathematics comes from life and serves life" by solving practical problems like 1, which embodies the basic concepts of "learning mathematics, using mathematics" and "applying what they have learned", making students realize that mathematics is a powerful weapon to solve practical problems and enhancing their awareness of applied mathematics.
Teaching Design of Algebraic Expressions of Plus-minus-3 Battlefield Training
First, compare who is the fastest and the best:
The coefficients of 1 and -0.4ab3 are degrees.
2. The highest term of the polynomial 3x2+2x-3x-4 is, the same term is, and the constant term is.
3. Remove the bracket 3a-(2 a b-3 B2+4)= 1
4. The polynomial whose sum with 2a- 1 is 7a2-4a+ 1 is
Second, apply knowledge and improve ability. You can do this:
It is known that Xiao Ming is twenty years old, Xiao Hong is two times younger than Xiao Ming, and Xiao Hua is one year older than Xiao Hong. Find the total age of three people.
The students scrambled to answer.
Students think independently, then do it in this notebook and find a classmate to write it on the blackboard.
Cultivate students' computing ability and ability to analyze and solve problems.
Review and reflection
What did you get from this lesson?
What problems should we pay attention to? (Show the knowledge structure diagram of this chapter:)
Teacher-student interaction combs knowledge. Understand the concepts, rules and related knowledge learned in this chapter, as well as their connections and differences, and write a knowledge structure diagram.
decorate
Operation p1926,8, 1 1
Blackboard design:
Review and reflection
I. Knowledge structure
Second, 1, algebraic expressions related concepts Note: single.
3. Addition and subtraction of algebraic expressions (Note: parentheses should be paid attention to when determining similar items)
Teaching reflection:
On the basis of students' full thinking, this lesson carries out group communication and class communication. In the process of reflection and communication, teachers and students draw the knowledge structure diagram of this chapter with the establishment of the knowledge system. In the whole process, they pay attention to both the summary of knowledge and the reflection and induction of the knowledge formation process. It leaves enough time and space for students to reflect on the occurrence and development of knowledge. However, due to the long time left for students, I feel very nervous in class, so I should pay attention to improvement in the future.