The first chapter "Little Bear opens a shop" is the lesson of Unit 4 "Divide and rule". The teaching objectives of this course are: 1. Combined with the problem-solving process, learn to use the multiplication formula of 2-5 to find the quotient, and realize the simplicity of finding the quotient with the multiplication formula and the close connection between division and life; 2. Understand the connection and difference of multiplication and division, and use multiplication and division to solve some simple practical problems.
The new curriculum standard requires not only teachers' teaching, but also students' learning. We should ask students questions according to the situation and try to solve problems through our own efforts, so as to stimulate students' interest in learning mathematics and improve their ability to solve problems. In the teaching design of this course, I make full use of the situation diagram to put forward the mathematical problems solved by addition, subtraction, multiplication and division respectively, with special emphasis on the problems solved by multiplication and division, to guide students to think, so that students can deeply feel the connection between mathematics and life, and can initially feel the reciprocal relationship of multiplication and division in mathematics. In the teaching process of this class, I paid special attention to solving the key question "How many toy tanks can 20 yuan buy?" At the same time, I also pay attention to let students learn to think with mathematical methods and improve their ability to solve problems with mathematics.
This design chooses activities suitable for students' age characteristics and attracts students' active participation in the form that students like. The design of activities not only needs students' wisdom, but also enables students to solve problems through cooperative inquiry, which meets the learning requirements of the new curriculum standard for students to explore actively, cooperate effectively and communicate fully.
Problems in teaching: 1. In the process of searching for mathematical information and asking mathematical questions according to the theme map of "Bear Shop", students put forward many problems that need to be solved by multiplication, and the types are repeated, and teachers did not guide them in time, which affected the efficiency of classroom teaching. 2. In the process of constructing the mathematical model of "multiplication formula seeking quotient", students were not effectively guided to discover independently, and the modeling process was too hasty. 6. The blackboard design needs to be further strengthened.
The second lesson is to further explore the calculation method of division (using division formula to find quotient) on the basis of students' understanding of the meaning of multiplication and division. In this class, I pay attention to creating situations to implement the whole link and the teaching concept of student development, so that students can learn independently and explore new knowledge.
1. Create problem situations to stimulate students' active participation in learning. At the beginning of this lesson, by creating a "little bear opens a shop" situation, the problems encountered by small animals in shopping lead to: 1) how much does it cost to buy four tanks; 2)20 yuan can buy some tanks. Students can successfully solve the first problem with multiplication formula and immediately find that they can calculate the product with multiplication formula. For the second question, students can't solve it smoothly.
2. Self-study and experience mathematics everywhere in life. Let students learn independently in teaching. For example, in solving the key question "How many tanks can 20 yuan buy?" Let the students try to answer, let the students speak their thoughts, let the students learn to think in mathematical ways, speak in mathematical language, and improve their ability to solve problems in mathematics. By combining examples in life, we can work out division problems, find mathematical problems in life, and cultivate students' initial application consciousness and ability to ask, analyze and solve problems.
3. Problems to be further explored. Of course, there are still some problems that need further improvement, such as how to improve the effectiveness of group cooperation. How to take care of individual differences and face all students in class is a problem worthy of discussion.
This is a division calculation class, and the focus of this class is to let students learn to find quotient by multiplication formula. But in the process of learning the understanding and meaning of division before, the calculation of division has penetrated into it more or less. Many students already know "I want to multiply, but I want to divide", but I don't explicitly tell them that I can use multiplication formula to calculate. So I think it should be easy for most students to learn and master the multiplication formula to get the quotient. Relatively speaking, many students still don't know how to list the division formula. For example, how many tanks can I buy for 20 yuan? If students are asked to fill in the blanks, they can finish it quickly. But the formula is a bit bad, just like some students in the class listed multiplication formulas. There are also many students who mix divisor with quotient. So in class, it takes a lot of time to calculate the formula. Why are students so vague about known conditions and unknown conditions? This is a problem that has never appeared in the old curriculum before. In this case, how should the teacher guide? These problems still need to be considered.