First of all, talk about the new curriculum concept and my design ideas.

The new curriculum standard of mathematics has arranged 100 million yuan in the knowledge system of number and algebra in the second classroom. After the teaching of number and calculator, its purpose is quite obvious. From the understanding of the number within 10,000 to the understanding of the number within 100 million and above 100 million, it is another expansion of the concept of student number. However, because the number 1 100 million is too large, it is difficult for students to get an intuitive feeling by combining specific quantities. Students often make mistakes when reading and writing large numbers, which is often related to the unclear concept of numbers and the lack of rich digital feelings. After the two units of "Understanding Numbers" and "Calculating with Calculator", this comprehensive application is arranged, so that students can experience the process of guessing, experimenting, reasoning and comparing through inquiry activities, and fully feel the number 1 100 million with imaginable materials. Let the students further understand the meaning of numbers and establish digital consciousness through their perception and experience of specific numbers. According to this goal, a new lesson "How big is 100 million" appeared in the new mathematics textbook of Jiangsu Education Press.

Activity is an important feature of mathematics learning. The new curriculum points out: "Teachers should provide children with sufficient opportunities to engage in mathematical activities and help them reveal laws, establish concepts, and truly understand and master basic mathematical knowledge and skills in the process of independent exploration, cooperation and communication." Combined with the age characteristics of the fourth-grade students and the characteristics of the teaching materials, I designed this class with various teaching activities throughout, such as "weighing", "counting" and "lining up in a row". Let students operate, explore independently, think with their brains, cooperate and communicate, acquire knowledge and cultivate their abilities in activities, and strive to create a three-dimensional open classroom atmosphere in which students are willing to learn.

Second, said the teaching objectives

After careful thinking and grasping, I have determined that the teaching objectives of this course are:

With the help of things that students are familiar with, knowledge and skill goals can feel 1 billion from different angles, and develop students' sense of numbers; You can answer the question about 1 100 million by multiple ratio or normalization, and you can handle more complex data with the help of a calculator.

Process and Method Objective Through the process of guessing, discussing and calculating, some strategies and methods to solve problems are obtained, and students' ability to solve problems is developed.

Emotion and attitude goal Experience the close relationship between mathematics and daily life, realize that many practical problems can be solved by mathematical methods, and realize the application value of mathematics; Cultivate the good quality of being willing to cooperate with others, communicate with others and solve problems together; Enhance environmental awareness and social responsibility.

Third, the focus and difficulty of teaching

According to the investigation and analysis of students' "learning situation" and the guidance of teaching objectives, I have determined the teaching emphasis and difficulty of this course.

Key points: After exploring the activities of 654.38 billion yuan, students can fully feel the number of 654.38 billion yuan with imaginable materials through the process of guessing, experiment, reasoning and comparison.

Teaching difficulties: experience and feel the application of large numbers in daily life, and further cultivate the sense of numbers.

Fourth, talk about my teaching philosophy (including my teaching methods and learning rules)

1, mathematics knowledge comes into life

Mathematical knowledge comes from life and is applied to life. In this lesson, I pay attention to starting from the students' reality and introducing new lessons from the perceptual experience of rice that students are familiar with, so that students can fully understand the mathematics in life. The design of this class is close to the reality of students' life, and the situation created conforms to the students' life background and experience. There is no doubt that this will be an ideal starting point for students to learn mathematics.

2. Subject knowledge integration

The development of students is a comprehensive problem, and mathematics should embody comprehensive ideas. We apply the concept of "grand mathematics view" to organically integrate mathematics with other disciplines. In teaching, mathematics is organically integrated with school life, nature, society, common sense, human geography and other knowledge, which fully embodies the humanistic concept that "mathematics is a human culture".

3. Diversified learning methods

The standard points out: "Students' mathematics learning contents should be realistic, meaningful and challenging, and these contents should be conducive to students' active observation, experiment, guess, verification, reasoning and communication." The standard also strongly advocates that "hands-on practice, independent exploration and cooperative communication are important ways for students to learn mathematics". Therefore, this teaching idea has been strongly emphasized in the design of this course.

4. Experience the learning process

The new mathematics curriculum view holds that process is a curriculum goal. "If students want to master mathematics, they must learn mathematics through inner creation and experience." In mathematics learning activities, students' thinking modes and intelligence levels are different. Therefore, in the process of mathematics learning, students must experience cooperation and communication as much as possible, feel different ways of thinking and thinking processes, understand numbers and mathematics thoughts through interactive experience, cultivate the consciousness of cooperation with others, and generate interest and confidence in learning mathematics.

Fifth, talk about teaching strategies and methods.

The design and implementation of this course is a difficult process, but also a process full of creativity and passion. I divide the teaching of this course into four parts.

Activity 1 Introduce the situation and cultivate the sense of numbers.

At the beginning of the class, I designed a short story, introducing "1 100 million", vividly showing the change of rice grains from less to more with multimedia courseware, and intuitively reflecting the changing process of students' understanding of logarithm from small to large. And question the figure of 65438+ 100 million grains of rice, and guide students to pay attention to new learning activities. It can not only stimulate students' interest in learning, but also naturally enter the main learning content of this lesson.

Design intention: This design highlights the reality of life and tries to create a process for students to abstract practical problems into mathematical models and explain and apply them based on existing life experiences.

Activity 2 Practical operation, initial perception

This link is mainly to estimate the weight of 654.38 billion grains of rice through the activities of a four-person group, so that students can initially feel the size of 654.38 billion grains from the perspective of quality. I can be roughly divided into six steps: the first step: the teacher asks questions. Can you guess the weight of 654.38 billion meters? (Students guess) Then the teacher continued to ask questions: Do we have any good ways to skillfully weigh 654.38 billion grains of rice? (Students discuss). Step 2: Teachers guide the design scheme: Weigh 1, 1, 100 grains of rice, divide by 100, then calculate the weight of 1 grain, and finally multiply by 1 100 million grains to calculate/kl. Scheme 2: First weigh 10g rice, then divide it by the number of rice grains, and finally multiply it by 1 billion to calculate the weight of 1 billion rice grains. Step 3: The teacher asks questions: Choose a scheme, work in groups of four, and calculate the quality of 654.38 billion grains of rice. Please write out the calculation process to facilitate the later report, and you can use a calculator to help with the calculation. Step 4: Students are divided into groups to calculate. Step 5: Each group reports the results, and the teacher writes on the blackboard to feel the amount of 65.438+0 billion grains of rice. Step 6: What do you think after knowing this information? (Educate students to cherish food)

Design intention: The process of students learning knowledge is a process of self-constructing knowledge and forming a "knowledge chain". Therefore, creating learning situations through group cooperative learning can greatly develop students' emotions, attitudes and values. And open teaching can effectively mobilize students' enthusiasm for learning and make them truly masters of learning. This design truly embodies the modern educational concept of "student-oriented development". In this link, students get some strategies and methods to solve problems, which pave the way for the next activities.

Activity 3: Cooperative exploration and re-experience.

Learning mathematical knowledge is not an end, but it is important to use this mathematical knowledge to solve practical problems in life. Because of the foundation of the last link, in this link, I fully mobilized the enthusiasm of students, let them boldly imagine and ask various questions about 654.38 billion. It also provides time and space for students to explore independently, cooperate and communicate, so that students can explore in groups on the basis of their own independent thinking and communicate with the whole class on the basis of group discussion. So in this session, I arranged two sessions: counting and arranging, 1 and counting. In this session, I arranged it like this: (1) Group activities, counting by hand. Group, each person takes some exercise books, mix them together, and count them one by one. When the number of people reaches 100, the teacher immediately tells each group the time spent, and the team leader records it. Time spent on communication between groups after completion. (2) Work in groups and ask questions. Dialogue: At this rate, how many seconds do we need for hundreds of millions of exercise books? Show the form in the book (90 seconds can be changed into seconds recognized by the whole class), and let the students calculate in groups and fill in the results. Feedback, named reading (3) Further exploration. Dialogue: 90 million seconds. Is that a long time? It is obviously inappropriate to express such a long time in seconds. What kind of time unit do you think should be adopted? How to convert (year) into how many years? After the students say the method, read the formula in the book. The students worked out the result with calculators. Question: What do you think of this result? Step 2 line up. Talk: Just now, by counting, we felt the size of 100 million in time. Do you want to feel the scale of 100 million again in other ways? (1) Actual measured length. Please 10 students stand in a row hand in hand, and the teacher and students measure the length together. (Take the whole meter) (2) List for calculation. Question: According to this calculation, how long will it take for 100 million children to stand in a row hand in hand? Show the form. According to the form, each group will also fill in the form according to the measurement data list just now and feed back the calculation results. (3) Further perceive the size of 100 million from the circle number of the earth. Read the calculated length by name. Dialogue: For this length, everyone will think it is very long, but how long it may be is not deeply felt. The equator of the earth is 40 million meters long, 1 100 million children stand hand in hand in a row. How many times can the equator of the earth spare? Do the math with a calculator. If a student's calculator can only display eight digits, it is necessary to change meters into kilometers. Name the calculation results. Question: How do you feel after reading this data?

Design intention: By allowing students to fully participate in operational and exploratory learning activities, cultivate their mathematical language expression ability and hands-on operation ability. By carrying out creative practical activities, students can gain a successful experience and stimulate their enthusiasm and confidence in learning mathematics well.

Activity 4: Combine practice to deepen understanding.

Connecting with things in life, through comparison, guide students to use imaginary materials in life examples, master the relative size relationship of numbers, and fully feel how big the number 1 100 million is. In the courseware, the data from our side, such as 65.438+0 billion drops of water, can be collected into about 3333 liters of water, which can hold 4 large water trucks.

1 100 million pieces of paper are stacked together, which is about 10000 meters high, which is higher than Mount Everest.

In recent years, China's wheat output has been stable at around 65438+ 100 million tons.

Xinmin Daily, February 26, 2004-The United Nations Food and Agriculture Organization announced on Wednesday that more than 6,543.8 billion chickens have been slaughtered in Asia where bird flu broke out.

In 200 1 year, the number of mobile phones in China has exceeded 1 100 million.

Design intention: provide rich materials in the form of words and pictures. Such concrete and vivid materials are closely related to life, so that students can form a vivid representation of logarithm and cultivate students to apply mathematics to solve practical problems in life. At the same time, these are the introduction of comprehensive knowledge, which can penetrate the education of students' love for the motherland and hometown. This kind of teaching makes students feel the close connection between mathematics and real life, which not only cultivates students' feelings of loving mathematics and life, but also develops students' sense of numbers.

Sixth, talk about the preset realization effect.

The idea of this lesson is always to carry out teaching activities around life, to make mathematics knowledge close to the prototype of life and to pay attention to students' learning experience. At the beginning of learning, students feel the change of rice grains from less to more through multimedia, and establish 100 million perceptual knowledge; In the process of learning, through practice, communication and cooperation with partners, students gradually improve their understanding of 100 million and form a more accurate rational understanding; Finally, students use these rational thinking to explore life, which has a deeper connection with 100 million people. The whole learning process properly embodies the learning process of starting from life, seeing the essence through phenomena, and finally returning to life and applying it to life, and has achieved good teaching results.

My basic idea in teaching this course is to take students' hands-on operation and independent inquiry as the main line, which runs through the whole classroom teaching activities and turns the process of students accepting knowledge into the process of students solving problems. The above is my superficial understanding of this lesson. I urge all leading teachers to give more valuable advice. Thank you!