Lecture Notes of Ten Minus Nine Minus Eight 1 I. teaching material analysis
1, the position and function of teaching materials
"Subtract nine from ten" is the first lesson of abdication subtraction within 20. It is taught on the basis that students have mastered the addition and subtraction within 1o and the carry addition within 20, and it is also an important basis for learning calculation in the future.
We should pay attention to new teaching ideas in the arrangement of teaching materials for this lesson. The designed situation not only conforms to the reality of students' life, but also arouses students' interest, so that students can initially feel the close relationship between mathematics and daily life. Two examples are arranged in the textbook of this lesson. Example 1 provides rich teaching resources for teachers to choose from. It reflects the diversity of algorithms, and students choose their favorite methods through analysis and comparison. The teaching of this course should allow students to calculate more than ten MINUS nine by a relatively simple method, and cultivate students' initial ability to ask and solve problems.
2. Education and teaching objectives
According to the above teaching material analysis, considering the existing cognitive structure of students, the teaching objectives of this course are determined as follows:
Knowledge and skills objectives:
(1) By exploring the problem situation, students can work out various methods to calculate ten MINUS nine on the basis of their own experience; By comparison, students can experience a simple calculation method.
(2) Make students understand the thinking process of abdication subtraction of ten minus nine and calculate ten minus nine correctly.
Program objectives:
(1) has gone through the process of collecting information, found mathematical problems, and initially realized that there is mathematics everywhere in life. Understand the value of mathematics
(2) The idea that things are interrelated has been preliminarily infiltrated.
(3) Through the choice of different methods, experience the joy of success and stimulate interest in learning.
3. Emphasis and difficulty in teaching
(1) has gone through the process of discussing the calculation method.
(2) Be able to calculate more than ten minus nine correctly and skillfully.
In order to highlight key points, break through difficulties and enable students to achieve the teaching objectives set in this section, I will talk about teaching methods and learning methods again.
Second, teaching strategies (speaking and learning)
The textbook of this course pays attention to the cultivation and exploration of calculation methods, puts forward mathematical problems through various vivid scenes, and encourages students to think systematically and connect with what they have learned, so as to develop their own independent learning and find effective learning methods suitable for them. In the process of calculation, we can get the correct answer through our own calculation methods and fully develop our logical thinking.
Thirdly, the analysis of learning situation.
This class is for 50 students in this class. The students have strong curiosity and thirst for knowledge. They have learned carry addition within 20 last semester and have a basic understanding of this unit. At the same time, students have certain life experience and pay more attention to the things around them. Participated in the study for a period of time and mastered some basic learning skills; Be able to make purposeful attempts according to the specific requirements of teachers, and have a certain practical ability, a preliminary sense of group cooperation, and a certain ability to observe and find problems. , are conducive to their learning process through thinking to find their own learning methods, and gradually form their own effective learning methods.
Fourth, talk about the teaching process
1. Introduce dialogue with "love" and "interest".
Every New Year's Day, there are interesting garden activities in the park. There are many children in the park on New Year's Day this year. (The picture is the textbook10 ~1/page Panorama of the Garden Tour). Please watch carefully. What are the children on the left doing in this garden? What are the children on the right doing?
2. Create a calculation method of situational awareness.
First, teachers use courseware to show the process of selling balloons, which is very close to students' lives and can easily stimulate students' interest in learning. On the basis of students' feelings about their situation, let the students ask their own questions and ask, "How many more?" problem Then let the students think, "Can you solve this problem?" Shift students' attention to the discussion of calculation methods. This lesson starts with 15-9. When explaining the basic idea of 10 minus 9, let the students think independently first, and then discuss the methods used in communication in groups with their learning tools. In this way, students not only have the opportunity to think independently, but also have the opportunity to communicate and cooperate with their peers, and finally exchange reports in the whole class. Encourage students to express their ideas in the report exchange. At this time, the basic thinking method of calculating 15-9 is fully displayed. Some students use the method of breaking ten, some students use the method of continuous subtraction, some students want to add and subtract, and some students use the method of 15- 10+ 1 The diversification of methods provides students with space for independent thinking, respects students' personality and develops students' thinking ability at different levels.
3, exchange and cooperation, learn to choose.
Teacher: When calculating 15-9, the students came up with so many methods, which one do you like best? Let's talk in the group first. Which method do you think is the best?
(1) Students discuss in groups.
(2) Students report their favorite methods.
The teacher asked: Why do you like this method?
In view of a variety of calculation methods, teachers provide students with an opportunity to compare and communicate, so that students can constantly compare and analyze each other to optimize their own.
Calculation method. Then share your favorite methods in class. In this way, a good calculation method is more clear and prominent. In this process, students not only learn the calculation method, but also cultivate the ability to collect and obtain valuable information and learn the methods to solve problems.
4. Migration exercise
(1) teaching ferrule diagram
The courseware shows the hoop diagram, and the students ask math questions according to the conditions. Then let the students answer the questions themselves. Tell me how it was worked out.
(2) Teaching examples 1
Show 12-9 =, organize students to think independently and calculate 12-9 in their own way. Ac algorithm.
Compare and discuss different algorithms.
After students get their favorite calculation method, let them solve other problems above ten minus nine, which can not only make students transfer the calculation method of 15-9 to other problems, but also make students feel the joy of success and pay attention to the cultivation of students' values.
5. Practice independently, consolidate methods and experience success.
(1) Complete the "Do it" question 1.
Let students work independently. For students with difficulties, let them use their own learning tools to set them up first, and then talk about the calculation process. When giving feedback, use courseware to demonstrate dynamically (for example, first set the bundle of 1, remove 9 from the bundle of 1, and then combine the remaining 1 and 1 into 2, so 1 minus 9 equals 2. Help them improve the basic algorithm of ten MINUS nine (or break ten, or add and subtract).
(2) Complete the second question of "doing".
In practice, to make students think independently, the thinking process of subtracting nine from ten is like this: circle nine from 10, and then add the remaining ones and digits to get the result.
(3) Complete the third question of "doing".
Teacher: Use your favorite method to calculate who is faster.
Students finish independently and revise collectively.
(4) Complete Exercise 2, Questions 1 and 2.
After the students finish speaking, let them think: How did the question of 1 work out 13-9? How are the second questions 12-9 and 15-9 worked out? (Break ten laws). Through thinking, we can further understand the operation of various algorithms.
(5) Help birds find their homes (courseware demonstration)
Let the students work out the formula on the bird first, and then correspond to the numbers on the house one by one. Teamwork, class review.
(6) apply what you have learned and solve practical problems.
The courseware returns to the situation diagram, and click to display the crossword diagram. Teacher: These children are playing crossword puzzles. How many crossword puzzles are there? How many children are guessing? How much did they guess? Courseware shows sounds and words: there are 13 crossword puzzles, and each of us guesses 1. Think about it, what questions can you ask?
In practice, various ways are designed to make students "play with mathematics", which makes simple mathematical calculation class interesting and the student participation rate is high. Create situations, guide students to find problems, explore ways to solve problems, and then use the explored methods to return to real situations to solve problems, so that students can experience the fun of learning success.
6. Share what you and I have gained
Ask the students after class: How many subtractions did you learn in this class? How to calculate this subtraction? What did you get?
Let each student talk to himself. Thirdly, guide students to summarize two general methods of subtracting nine from ten: ① reducing thinking and ② breaking ten.
Cultivate students' inductive ability and language expression ability, and students sum up and complement each other. Teachers only give proper guidance, cultivate students' ability of induction and generalization, and encourage students to evaluate themselves from the aspects of mathematical knowledge, mathematical methods and mathematical emotions.
Draft of "Ten Minus Nine Minus Eight" 2 Today, I said that the content of the first lesson in Unit 1 of Grade One in primary school mathematics is "Ten Minus Nine". The teaching of this course is based on the fact that students have learned carry addition within 20 minutes and addition and subtraction within 10. At the same time, they are also ready for the next study: subtract 8 and 7 from a dozen digits, and subtract one digit from the abdication subtraction in the future. The example first puts forward the question of "how much is left" according to the living conditions of the peach monkeys. Guide the students to list the layout of 15-9. Then let the students contact the existing knowledge and life experience, think about the algorithm independently, and then arrange exercises such as looking at pictures, moving cards and comparing problem groups. Stimulate interest by "thinking while doing" and consolidate the arithmetic of subtracting nine from more than ten. The teaching focus of this course is to let students master the calculation method of subtracting nine from more than ten through hands-on operation, independent exploration and cooperative communication, and the difficulty is to understand the arithmetic of subtracting nine from more than ten.
Based on the analysis and understanding of teaching materials, as well as the cognitive rules of first-year students, I have formulated the following teaching objectives:
1, let students go through the process of putting forward and solving mathematical problems from the actual situation, let students sum up the algorithm of subtracting more than ten from nine on the basis of existing knowledge, and correctly calculate the related exercises of subtracting more than ten from nine.
2. Let students gradually cultivate the consciousness and ability of inquiry and thinking in observation and operation, realize the diversity of algorithms, and develop innovative consciousness and flexibility of thinking.
3. Let students strengthen communication on the basis of independent thinking, experience the happiness of cooperation with their peers, and establish a sense of cooperation and communication.
Focusing on the teaching objectives and the actual situation of students, I teach in four links:
The first link: review and pave the way. First, show the oral arithmetic problem of carrying addition within 20 and nine questions with brackets equal to more than 10, so that students can calculate. By reviewing the old knowledge, they not only consolidated the oral calculation method, but also found the starting point of new knowledge migration, preparing for the correct and smooth migration.
The second link: create the scene and explore the algorithm. I will organize students to explore new knowledge in three levels.
1 grade: ask questions from the life situation, and demonstrate the situation of the little monkey selling peaches with multimedia. *** 13 peaches, and the little rabbit bought nine. Then the teacher asked: What math questions do you ask yourself according to the situation of selling peaches? How to form? Can you answer that? According to the students' answers, the formula 13-9 leads to the topic: this is the new knowledge we are going to learn today-ten MINUS nine. Here, questions and formulas are extracted from students' familiar life situations, so as to arouse students' enthusiasm, generate the desire to solve problems and actively participate in the activities of exploring new knowledge.
The second level understands arithmetic through operation. I estimate that individual students vary greatly. Some students have early preschool education and can get figures quickly, while others have slow thinking. In view of the students' situation, I encourage them to swing and hold them with sticks. ① Students operate independently and talk while operating. ② Communicate at the same table. ③ Communication and discussion between teachers and students. ④ Report the calculation results. Experiencing different algorithms. Ask students to exchange their own algorithms and compare several algorithms. 13— 1— 1— 1— 1— 1— 1— 1— 1— 1=4,
10-9+3 = 413-6 = 4 Because of the design of 9+4 = 13, 13-9 = 4, it provides a platform for students and teachers to communicate with each other, so that each student can fully express his different ideas.
Level three. Consolidate the algorithm and get strengthened. ① Question: What other questions are more than ten minus nine? Who can give an example? According to the students' answers, the teacher wrote on the blackboard:14-917-916-918-915-9/kloc-0.
12—9② What method do you like to calculate? After the calculation, communicate the algorithm with the students in the group. Here, by giving students examples, we can improve all the equations of more than ten MINUS nine, and further explore the calculation method of more than ten MINUS nine, so that every student can participate in the learning process, choose the method that suits them, cultivate the order and orderliness of students' thinking, and gradually master arithmetic.
The third link: deepen the application and form oral calculation skills. Here I have designed the following three levels of exercises.
1, basic exercises (ten MINUS nine) Finish thinking and doing 1, 2, 3, mainly to consolidate the calculation method of ten MINUS nine and help students form calculation skills.
2. Use teaching cards and media demonstrations to practice in the form of games. With the movement of numbers, students can say the number after subtracting 9, so that they can practice repeatedly and gradually improve their proficiency in calculation.
3. Arrange all the formulas of more than ten MINUS nine in a certain order, let students fill in the numbers of each question first, and then guide students to compare the similarities and differences of these formulas through discussion, find out the arrangement law of the formulas, and then realize that they can use this law flexibly to calculate.
These three levels of exercises are diverse, distinct and gradual, guiding students to discuss on the basis of mastering the algorithm, optimizing their thinking and forming oral calculation skills.
The fourth link: class summary. What did you learn in this class? What did you get? What method do you like to calculate? What else don't you understand?
By asking students to summarize the content of this lesson, students can have a process of sorting out what they have learned today, and students can complement each other and improve the calculation method, which is conducive to the cultivation of students' learning ability and experience the happiness of learning success.
In this class, I completely follow the student-centered teaching principle, encourage students to observe, operate, communicate, compare, reason and summarize, fully develop students' thinking ability, cultivate the flexibility of thinking, and let students acquire knowledge through independent exploration and cooperative communication.
Speech 3 of "Ten Minus Nine Minus Eight" Hello, judges! I said that the content of the class is the lesson of Unit 7 "Buying Pencils" in the first volume of primary school mathematics published by Beijing Normal University. The teaching links are as follows: teaching analysis, teaching objectives, teaching difficulties, teaching process and teaching media design ideas.
First, teaching analysis:
This lesson is the beginning of learning abdication subtraction in 20 years. It is based on students mastering carry addition and subtraction within 20 years and addition and subtraction within 10 years, which paves the way for students to learn addition and subtraction within 100 years in the future. Through this lesson, students are encouraged to think independently and try boldly, so as to have a new understanding of the essence of mathematics.
Second, the teaching objectives:
Knowledge and skills: can correctly calculate more than ten subtractions of 9 and 8, and can be simply applied.
Process and method: Using the existing life experience and knowledge, explore the abdication subtraction of more than ten MINUS ninety-eight.
Emotional attitude and values: cultivate the study habit of being good at thinking and listening, and understand other people's different algorithms.
Third, teaching focuses on difficulties.
Teaching focus:
1, learn to correctly calculate the abdication subtraction of more than ten MINUS nine and more than ten MINUS eight.
2. Understand one or more different calculation methods.
Teaching difficulties:
Diversity of perceptual computing methods.
Fourth, the teaching process
The teaching process is divided into the following three links:
The first link: create a situation to stimulate interest. (network)
The second link: explore the algorithm and solve the problem. (Multimedia)
The third link: expanding activities and comprehensive training. (Multimedia, Network)
The first link: create a situation to stimulate interest.
First, I create a situation: "Do all children like to play games? In this class, we will play a target darts game together. " Ask math questions according to the number of times students play darts. "In this lesson, we will first solve the problem of 15-9=." This leads to a new lesson. Here, I changed the teaching scene, designed the theme picture of rabbits buying pencils from kangaroo stationery store as a target darts game that students are familiar with and interested in, moved the game to the classroom, and let the children participate in it personally, so as to truly feel the close connection between mathematics and real life. Finally, this change of scene design has achieved more enthusiastic and outstanding teaching effect in teaching practice.
The second link: explore the algorithm and solve the problem.
Exploring the calculation method of more than ten MINUS nine MINUS eight is the teaching focus of this lesson.
1, independent thinking 15-9 algorithm: students organize their own ideas through independent thinking and fully express their opinions in group communication.
2. Group communication: This link makes the group cooperation concrete according to the teaching discussion with the help of the network, and the communication within the group is not a mere formality, thus achieving the teaching goal, cultivating the study habit of being good at thinking and listening, and understanding other people's different algorithms. So when I asked the students to tell the prepared algorithms to the children in the group in turn, I put forward specific requirements. Pay attention when communicating: (1) Try to make it clear so that everyone can understand what you say. (2) Pay attention to other people's speeches and don't repeat what you have said.
3. Report to the whole class: guide students to find reasonable and simple algorithms in the interactive process of listening, speaking, discussing and thinking, cultivate students' awareness of optimization, use multimedia to show the four key methods of this lesson, give freshmen with weak ability to distinguish right from wrong a thinking space but make correct guidance, which not only embodies the leading role of teachers, but also gives full play to the main role of students, and finally forms students' understanding of "abdication and subtraction within 20 years"
4. Students choose their favorite method and try to practice 15-8 =?
The third link: expanding activities and comprehensive training.
This link is based on a rabbit's basic application training and thinking development training (17-9), which runs through the development of a series of stories such as "Little Rabbit Carrying Radish" and "Sending Little Rabbit Home".
It not only gives full play to children's creativity and imagination, but also allows them to spread their imagination wings in an atmosphere full of vitality and fun and feel the fun of learning.
Five, teaching media design ideas
1 multimedia integration point: use multimedia to create situations that conform to students' cognitive psychology, one story after another, like cartoons that attract students, give full play to teachers' leading role and students' dominant position, and let students easily understand new knowledge.
Network integration point: I invited several senior teaching leaders and teachers to help me review this lesson, but due to the busy work of the head teacher in the regional peace time, it is really difficult for us to get together and discuss, which really makes me embarrassed. Later, I used our teacher's blog in Heping District to communicate and discuss, where I published my teaching design, and soon got more teachers' comments, so this thorny issue was hardly a problem. More teachers should be involved. Later, after three attempts, many online discussions and many improvements, I finally came to today's national competition with the wisdom of many teachers.
3. The integration of information technology and normal teaching has been effectively carried out: I chose an ordinary and normal computing teaching course instead of a special course with free use of the network and a lot of room for network development. Its integration function benefited me a lot, which made me have a brand-new understanding of the new curriculum concept and the integration of information technology and curriculum, greatly improving my teaching vision.
Thank the organizing Committee for giving me such an opportunity. Thank you, judges and teachers. This is the end of my lecture.