Reflection on the teaching of multiplication and multiplication

Part 1: Reflection on the teaching of multiplication and multiplication

1. From the actual introduction of this class, a problem scenario was created.
The new curriculum standard proposes “Let students learn mathematics in vivid and specific situations.” I started to buy homework from the class at the beginning of the class, recreating the familiar scenes of the students, inspiring the students’ interest in learning, and calculating the settings in the students. In the specific scenario, the students' original knowledge and experience are activated, so that students are willing to actively explore knowledge.
2. Starting from the students' existing knowledge and experience, they have created a space for thinking and communication.
The new curriculum standard proposes to “guide students to think independently and communicate with each other”, “enhance estimation and encourage algorithm diversification”. In the process of exploring the calculation of the multiplication, I first asked the students to estimate and estimate that the number of homework was about 40, which cultivated the students' ability to estimate. Then, let the students use their existing knowledge and experience to calculate. The students actively participated in the exchange discussion. Many students have strong oral calculation ability, and calculated the results by means of oral calculation. In the exchange, the students fully experienced the joy of success. On this basis, I also guided the students to try to solve this problem in a vertical form. With the basis of oral calculation, the students came up with a method of multiplication by means of serious thinking and cooperation. From the use of existing knowledge to solve problems, to the mutual exchange of exploration and calculation methods, students are always in the main position of learning. In the activity, students have experienced the process of calculating the calculation method of writing multiplication, and realized the usefulness of calculation, which has truly become learning. the host.
Of course, there are also deficiencies in the classroom. For example, in some children who have less speech and introverted, in the cooperation and exchange, the depth of participation is far less than that of the lively and cheerful children. This requires me to continue to teach in the future. Summarize experience, improve methods, and truly "everyone learns valuable mathematics; everyone can get the necessary mathematics; different people get different developments in mathematics."

Part 2: Reflection on the teaching of multiplication and multiplication

This class is based on the fact that students have mastered the two-digit by two-digit calculation method, and the focus is on the method for students to master the position. I intend to highlight the temperament of the classroom, based on the improvement of students' effective learning ability. Let students think about finding a 19×19 method, allowing different expressions, such as estimation and vertical calculation, to build a rich learning platform through the display of diverse algorithms to provide opportunities for thinking collisions, allowing students to communicate independently and fully demonstrate Students at different levels of thinking, learning from each other and promoting each other, thus creating an equal and relaxed learning atmosphere.
I first reviewed the addition calculations related to the newly taught teaching and the double-digit multi-digit non-input calculations, which not only aroused the students' old knowledge, but also prepared for the teaching of the new class. Because the order and calculation process of the 19×19 multiplication in this lesson is the same as that of the previous one, only the carry-in is in the process of calculation. Therefore, the teaching of the new lesson is mainly based on the self-study of students. First, the students interact with each other in the group. Communicate your own difficulties and gains in the calculation process, and finally report collectively in the class. From the student report, I found that most of the students have mastered the calculation method, which is a problem in the accuracy of calculation. Therefore, in the following teachings, I focused on strengthening the education of the students in the calculation of the side. I also fully allow students to practice in different forms to improve the accuracy of student calculations. After teaching this example, I specially showed a warm reminder: remind the students not to forget to add the number of the carry-in! Then there are a few questions to show the filling, layering exercises, after the students complete Speaking the method of calculation, the purpose is to let students feel in the process of calculation, summarizing the two-digit multi-digit calculation method. From this lesson, students are actively involved and have a strong interest in learning. This foundation is due to the two-digit multi-digit multiplication multiplication that students learn in the previous lesson of this semester. Therefore, in this lesson, I will let the students try to calculate the calculations themselves. Let me say that I want to let the students think and calculate the two-digit multi-digit calculation method. When letting students calculate "19×19", I consciously arranged four students to play on the blackboard, let the students observe the discussion and find the correct calculation method, thus breaking through the teaching difficulty of “carrying”. Then, a group of corrective questions was organized to organize the collective correction of the students, summarizing and mastering the calculation method. The students mastered the calculation method in the consolidation training.
In the teaching, I realized that the teaching of this knowledge should not be anxious. It is not easy to see whether the results calculated by the students are correct or not. It is also necessary to pay attention to whether the students understand the arithmetic. The seemingly simple calculations are actually quite difficult for the first-time students. In the teaching, we should observe more about the reasons for students' mistakes and help them to correct the symptoms. At the same time, strengthening the understanding of arithmetic is the key to students' proficiency in computing methods.

Part 3: Reflection on the teaching of multiplication and multiplication

At the beginning of the week, I learned the multiplication method. First, I learned the multiplication method. The problem is not very big. After learning the carry multiplication, the problem arises. I think the reason is:
1. The student's calculation base is poor. Some of the students' oral calculations add and subtract are not enough in themselves. The multiplication method is a mess. In the carry multiplication, the calculation process has multiplication and addition, which is even more difficult for these students.
2. The reason does not understand. Some students do not understand the calculation of the vertical calculation. For example, the students who are ahead of the number are added at the highest position; and some students enter the number and multiply. So the mistakes are all over.
3. There are many calculation steps. The multi-digit multiplied by one digit is not the multiplication of the numbers on the same digit. Instead, each digit is used to separate each digit into another factor, and the resulting product is added to the digit of the carry. There are many problems to be considered, and students are prone to errors in the calculation process.
In response to the above questions, I think the solution is:
1. Strengthen oral training.
2. Strengthen students' understanding of computing.
3. Intensive training is carried out until it is mastered.

Part 4: Reflection on the teaching of multiplication and multiplication

When I was teaching the first lesson of "Big Multiplication", the content of this lesson was the course of learning the "Big Multiplication" and the basis for further learning multi-digit multiplication. It is based on the students who have mastered the multiplication in the table, and learned the whole ten, the hundred-digit multi-digit calculation, the multi-step and the two-step calculation, and the composition of the number. The knowledge goal of my teaching is: 1. With the combination of calculation and use, let students understand the necessity of multi-digit multiplication and single digit calculation. 2. Through the combination of calculation and use, let students experience the process of multi-digit multiplication and single digit calculation, and initially establish a multiplication vertical calculation model to understand the meaning of each step of the vertical type. The ability goals are: 1. In the process of learning, let students experience the diversity of computing methods. 2. The creation of a living situation allows students to experience the connection between mathematics and life, and consciously cultivate students' ability to estimate and use knowledge transfer and analogy in the process of solving problems. 3. Through the solution of problems, cultivate the diversity of students' problem-solving strategies.
After finishing this lesson, I feel that some places are still very successful.
First, based on the problem-solving background, the situation is written as a teaching service.
For example, I created a situation of “donating books for children in the earthquake”, letting students experience the process of interpreting information, asking questions, and solving problems, fully embodying students as the main body. In the process of solving the first problem, first of all, let the students understand the necessary necessity of the calculation; at the same time, through several measures to clarify the arithmetic and algorithm. Finally, through comparison, the estimation, oral calculation, and calculation are linked. Ask the students what you found, the conclusion is that the method is the same, let the students understand the reasoning more deeply, and feel the inner relationship between the knowledge, and never change from it. The solution to the second problem is to consolidate the two-digit by one-digit arithmetic and algorithm. The third problem is solved by letting students experience multiple strategies for solving problems, letting students know that they think differently from different angles, and the calculations are different, but the results are the same. In the comprehensive exercise, I created a situation in which “teachers donate clothes for people in the earthquake”. The goal is to consolidate the multi-digit multiplier and let the students experience the diversity of algorithms.
Second, let students take the initiative to learn, taking the students' existing knowledge as the starting point.
When solving the first problem, let me ask the students to estimate and ask: Can you estimate? How to estimate? Estimated or estimated? Because I have just learned it before, it is easy to wake up the students' existing knowledge. After the assessment, ask the students, can you count? It not only plays the role of review, but also plays a role in laying the foundation, and also reflects the knowledge starting point of respecting students. Through guidance, let students understand the necessity of multiplication of the pen and start a new lesson.
Third, the practice design has a mental increase.
Basic questions: a set of pen calculations. 3×2 23×2 223×2 The previous calculations are all two-digit multi-digit numbers. In this group of questions, there are three digits multiplied by one digit. Let the students first talk about 223×2 arithmetic and algorithm. Then let the students compare the three calculations and draw conclusions through comparison. The method is the same, and then add a 2 in front of 223 to let the students feel.
Comprehensive question: Teachers donate clothes for the disaster area. On the basis of mastering the pen and multiplication, let students experience the diversity of algorithms.
The combination of number and shape: first estimate and then calculate. Move first and then count.
There are still some problems in this lesson:
First, in the face of multiple solutions for students, you can stand taller. When solving the third problem, let the students classify and classify according to the different ideas. It will help to develop students' ability to solve problems.
Second, 31 × 2 + 33, should ask the students what does 31 × 2 mean? Rather than just solving problems with new solutions, it is necessary to guide students to analyze the meaning of the questions.
Third, in the comparison of oral calculations, the calculation of the same place, the need to communicate in advance, the first to let the students understand, the teacher and researcher Tian teacher gave a suggestion: When let the students calculate, the process of the book down, say what 6 said, What does 3 mean? After the calculation, and then contrast, there is a basis for comparison.

Part V: Reflection on the teaching of multiplication and multiplication

The teaching content of this lesson is a two-digit multi-digit two-digit calculation of non-receipt. It is a calculation of the two-digit multi-digit number, a two-digit multi-digit calculation, and a two-digit multiplication. The two-digit estimate is based on further learning. It is the focus of this unit. After students have mastered the two-digit by two-digit calculation method, they will multiply the two-digit multiplication by two digits for the student. The multi-digit multiplication problem laid the foundation. Therefore, the calculation of this lesson is mainly for students 1 to master the order of multiplication; 2. To understand how many "ten" is multiplied by the number of the second factor by the number of the first factor, the last digit of the multiplied number is Align with the ten digits of the factor. Traditional computational teaching focuses on enabling students to master computational methods and perform calculations correctly. In the context of the new curriculum, computational teaching is not isolated, it is combined with estimation and solving practical problems. Therefore, this lesson focuses on the teaching objectives: 1. Let students experience the two-digit multi-digit calculation process, and understand and master the two-digit multi-digit arithmetic. 2. Through independent and cooperative learning, explore the calculation method of two-digit by two-digit number and diversify the experience method. 3. Cultivate students' cooperative learning awareness and infiltrate moral education. At the same time, students are trained to use the "old knowledge" to solve the "new knowledge" learning method and the learning quality that is good at thinking, and to develop a serious calculation of learning habits. The difficulty of teaching is still to understand that the multiplier is the arithmetic of two-digit multiplication.
The teaching process of the whole class is to create a situation of buying Fuwa to stimulate students' interest in learning. At the same time, a situation of buying a book is built around the central problem to be solved. In the teaching, I lead the students in the role of the leader. Clear: 1. Master the order of multiplication. 2. Understand how many "ten" the first factor is multiplied by the number on the tens of the second factor, and the last digit of the multiplied number is aligned with the tenth of the factor. Algorithmic diversification is also advocated.
In the course of exploring the new knowledge, this lesson is divided into two levels in order to break through the key points and difficulties. The first level is mainly to solve the students' understanding of the two-digit by two-digit arithmetic, and the understanding of the mathematics is mainly based on the students' understanding of the meaning of the multiplication formula as a breakthrough. In the comparison of oral calculations and column verticals, students like the algorithm of oral calculations, so I said in a row: "In fact, the oral calculation is the same as the vertical algorithm. The vertical method is simpler than the oral calculation method. In fact, The vertical column is also the product of 24 times 2; the product of 24 times 10 is calculated; the product of 24 times 2 and the product of 24 times 10 are added." The second level is mainly to solve the pair of tens of partial products. This is also a difficult point in this lesson. It is mainly to solve these problems. Can the "0" at the end of the second partial product be saved? Will it affect the calculation results? What should I pay attention to after saving "0"?
In short, this teaching and research course can grasp the basic steps of computational teaching: 1. Strengthen the oral calculation and estimate. 2, attach importance to arithmetic. 3. Pay attention to algorithm diversification. 4. Have the awareness of cultivating students to cooperate and learn independently. But "there is no perfect classroom", this lesson also has shortcomings and needs to be improved: 1. The student's subject status is not well reflected, the teacher explains more, and the students show less time and space. 2. The key links are single and repeated, and the process of students understanding internalization is not reflected.
In the future teaching, we should let every student actively participate in the learning process through hands-on, brain-moving and vocalization. When teaching in key links, students should be told the order of the multiplication, understanding and telling the second. The number of tens of digits is multiplied by the number of "ten" by the first factor, and the last digit of the multiplied number is aligned with the tenth of the factor. Let students reflect the value of self in the time and space created by teachers and taste the joy of success. At the same time, the algorithm is diversified and optimized, and students are exposed to the mathematical thinking method of “resolving new knowledge with old knowledge”.