Reflection on the teaching of subtraction within 5

Reflection on the teaching of less than 5 within the teaching method :

The lesson of "subtraction within 5" is the main basic subtraction operation, requiring students to correctly and skillfully calculate based on the understanding of the calculation method.
As the teaching of the first class, I still let the students start from the basics, from the meaning of recognizing the subtraction, let the children themselves understand why they use subtraction to calculate? When should I use subtraction to calculate? In the teaching process, on the blackboard, I drew the scenes of "the original five birds in the tree, and then flew away two" and "there are five big apples on the tree, blowing one for the wind" and so on. Look at the picture and say what they saw, let them understand, "fly away, fall down, drive away" and so on, use subtraction to calculate, infiltrate the meaning of subtraction. When the children understand the meaning of subtraction, they will understand more when they calculate.
Oral calculation is the basis of calculation. Therefore, in the mathematics of small and medium-sized mathematics, it is necessary to attach great importance to oral training. Especially in the lower grades, the "addition and subtraction within 20" must be proficient, and the "addition and subtraction within 5" is the cornerstone. The more stable this cornerstone is, the easier it will be to learn the following. In the teaching of this unit, it is not difficult to find the oral calculation method, and the correct rate and speed of the oral calculation are the key points. Therefore, we must focus on how to stimulate students' interest and improve students' oral ability. Through the creation of situations, various competitions and other means, in the teaching, the use of oral calculation cards, the use of games such as answering, driving, group competitions, men's and women's competitions, etc., students actively participate in the game, so that students improve the speed of the mouth in the game . The improvement of the oral calculation ability is not overnight, and must be practiced more. In addition, it is necessary to cooperate with parents to let parents practice a certain number of oral calculations that are synchronized with the teaching content.
If this is done, after a period of training, the student's oral calculation ability can certainly be improved.

Intra-subtraction teaching lesson 5 :

This class mainly allows students to understand the meaning of subtraction and the subtraction that can be correctly calculated within 5, and cultivate students' mathematical expression ability and reasoning ability.
1. Understand the meaning of subtraction in the context.
At the beginning of the teaching, I directly presented the situation map, let the students observe the two pictures in turn, consciously let the students use three sentences to express the meaning of the picture, realize the transformation of the life situation to the mathematics problem, and cultivate the students' problem consciousness. Then ask the students to think "what kind of formula can be used to represent?" "What does this formula mean?" Through the solution of these problems, the abstract formula is linked to the specific situation, and the specific meaning of the subtraction formula is assigned.
For the test, I asked the students to use the three sentences directly to describe the formula, and to list the formula according to the meaning of the figure, and to say that the formula is the meaning, let the students experience the observation picture - the language expression - list the formula - Understand the problem-solving process of the formula, realize the specific to the abstraction, and further understand the meaning of the subtraction formula.
2. Further understand the meaning of subtraction in communication.
If you only rely on two situational maps to understand the meaning of subtraction, it is not profound. Therefore, after teaching examples and trying, let students compare and think: Why are these two questions calculated by subtraction? What other problems in life should be calculated by subtraction? Through the exchange of these questions, the students' vision of subtraction of knowledge has been extended to life. In the teaching, some students said: "I brought 2 apples, ate one, and a few?" and the children said: " There are 5 words on it, 1 is erased, and there are still a few words?”... Activate the students’ existing experience, and combine life mathematics with school mathematics to provide rich representation support for students to learn subtraction.
3. Master the algorithm of subtraction in practice.
The textbook arranges three levels of practice. The first level is to take a look. If you want to do the first question, let the students perform column calculation on the basis of observation and expression, and communicate the relationship between the situation and the formula. Deepen the understanding of the meaning of subtraction. The second level is a move, think about the second question, let the students do the work, and understand the algorithm through the operation of graphics. The third level is to think about it. If you want to do the third question, the fifth question, let the students directly use the calculation method to calculate the result. Of course, in this process, because the students have different knowledge and experience, the students may Different algorithms are used, such as students may use finger-sharing, and students may use the number of points to solve. For these methods, we can temporarily optimize and let students experience and feel.

Rethinking Fan Wensan under the teaching of subtraction within 5 :

The lesson of "subtraction within 5" is the main basic subtraction operation, requiring students to correctly and skillfully calculate based on the understanding of the calculation method.
First, combine the courseware to understand the meaning of subtraction.
As the teaching of the first class, I still let the students start from the basics, from the meaning of recognizing the subtraction, let the children themselves understand why they use subtraction to calculate? When should I use subtraction to calculate? In the teaching process, through the courseware demonstration "There are 5 children, then two went" and "There are 3 children on the swing, walked one" and so on, let the children look at the picture and say they Seeing, let them further understand, "fly away, fall down, drive away" and so on to use subtraction to calculate, the meaning of penetration subtraction. When the children understand the meaning of subtraction, they will understand more when they calculate.
Second, combined with the process of saying meaning, the column subtraction formula.
The subtraction list has certain difficulty compared to the addition, so before the column, I let the students combine the meaning of the figure, use three sentences to talk about the meaning of the figure, and list the formula according to the figure. "There are, gone, left," and guide students to observe and think: from which part is reduced? Subtract that part? To sum up, you must remove the flying away part from the original total, and you can't use the rest to reduce it. Although there is a certain improvement, there are still mistakes, and it is necessary to exercise more and develop a good habit of saying the meaning of the formula.
Third, use a variety of methods to practice oral calculations and improve abilities.
In the teaching of this lesson, it is not difficult to find the oral calculation method, and the correct rate and speed of the oral calculation are the key points. Therefore, we must focus on how to stimulate students' interest and improve students' oral ability. Through the creation of situations, various competitions and other means, in the teaching, the use of oral calculation cards, the use of games such as answering, driving, group competitions, men's and women's competitions, etc., students actively participate in the game, so that students improve the speed of the mouth in the game .

Intra-subtraction teaching lesson 5 :

In October, I took a lesson, "Subtraction within 5". After class, after listening to some teachers' comments, I reviewed the whole process. Let me talk about my views on this lesson:
1. Focus on cultivating students' ability to express. Einstein said: "It is often more important to ask a question than to solve a problem." Therefore, it is particularly important to gradually develop students' ability to ask questions from the first grade. In this teaching design, I have consciously infiltrated this idea. In the teaching examples, students are guided to raise mathematics questions and initially develop students' questions and expressions. Most of the students' language skills are good, and they can fully explain math problems. In order to allow more students to speak, I also use my own methods, the same table to teach students to develop their language skills.
2, classroom organization is in place: I used: to see who is doing well, to see who is the best sitting; who's eyes are the most beautiful; who is the first language to organize classroom discipline. Therefore, most of the students in the whole class focused their attention, listened carefully, and actively raised their hands to speak. The classroom atmosphere was very good. However, such times may be excessive, affecting the fluency of the entire link and the teaching effect. In the future class, we must grasp the measure.
Next, talk about your shortcomings:
1. The language is not concise and vivid. In the teaching last year, I was often accused by the master, saying that my voice is too ugly, I think this will not only say my tone, but also the vividness of my language. I often admire the language teacher to express in a language that is so soft and fairy-tale. In today's class, I didn't pay attention to my own language. After asking other teachers, I found that I might be nervous, the language expression was awkward, the expression was not smooth, and even a mantra or "party language" appeared. It is very bad, and I have to change it later. How to improve the vividness of the language, I feel that I can listen to the lesson of the Chinese teacher, learn the tone of their voice, and use it in their own teaching.
2, the evaluation is not in place: Today, down, some teachers asked me, you will evaluate the students, but you will only evaluate those students who perform well, and some actually say that he is not bad, but it is still a little worse. Students, you will criticize him, this will hit their confidence. When I have a good drink, I also pay great attention to the evaluation of students in the usual classroom, and the evaluation is considered good. Now I want to come and find out that I have such a problem. In the future, I will treat those middle and lower students in an encouraging language and build their self-confidence.
3. The biggest problem today is that it does not highlight the significance of subtraction. In the classroom, I directly help students to summarize the meaning of subtraction in the form of a summary of teachers. It is obvious that many students do not understand, they do not know when they ask them what is subtraction after class. They still stay in the surface of the example, not deep. Therefore, in the work, there are cases such as 2-1=1. This shows that my work is still not in place, and I exchanged with the master after class. If I say 5 in the example, what is it, -2? 3? When you can continue to ask: that is, where to remove 2, in fact, is to remove 2 in the total; or in the example, when the subtraction formula appears, ask: Why do you use subtraction? If you ask a few more times, the students will understand that removing part of the total will be done by subtraction. It seems that in the future, the difficulty of teaching materials will be more difficult to think about in teaching, and find simple and effective methods.
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I find that there are still many shortcomings. I hope that through continuous study and hard work, I can continue to improve myself.

Intra-subtraction teaching lesson 5:

The addition and subtraction method within 5 is based on the student's requirement to master 10 points and combinations. It is the basis of addition and subtraction within 10, and is an important basis for learning addition and subtraction calculation and solving practical problems. Some children are After reading the kindergarten, most of the children have a good grasp of this part. Therefore, I put the focus of teaching on the connection between the calculation of perceptual numbers and life. In the specific situation, I will appreciate the meaning of addition and subtraction, as follows:
1. Contact the actual life and let the students realize that mathematics is everywhere:
In the classroom, I try to list the things around the students to create scenarios for students to participate in, so that they can find problems and ask questions. Students are very interested. For example, when teaching additions within 5, first show the scene map of the chicks, guide the students to observe independently, exchange and discuss at the same table, and realize that the original 3 and the 2 are combined to have 5 . At the same time as the teacher's summary, the students use gestures to further understand the meaning of addition and "combination." Secondly, in the process of students reading the formula, further deepening the understanding that "to combine the two parts" needs to be calculated by addition, which fully mobilizes the students' interest in self-exploration, and further enriches students' understanding of addition, and initially understands the addition. Can solve the problem.
2. Practical use and consolidate the understanding of addition.
First of all, present the “Thinking and Doing” physical map, let the students list the addition formulas by observing and exchanging the information obtained; on the basis of this, present the “Thinking and Doing” Question 2, and the students will draw the graph and calculate. On the one hand, continue to consolidate the understanding of the meaning of addition, on the other hand help students master the calculation method.
Secondly, deepen the practice. After getting rid of the specific graphics, the students directly apply the combined ideas to calculate the third question. In the communication, help the students to further master the algorithm, and at the same time, through practice, standardize the writing format of the students and give people a appreciation of mathematics.
Once again, the practice is applied, and the theme map of the fourth question is presented, which is completed independently on the premise that the students freely express the meaning of the question, and the ability to develop the complete expression of the students in the whole class communication; in addition, the game is not only helped by the game of calculating the post-letter letter. Calculate the addition within 5, and experience the connection between mathematics and life, let students enjoy the joy and value of mathematics success.
In short, in teaching, I actively advocate the diversification of algorithms and provide students with opportunities for mathematics communication. The purpose is to promote students' mathematical thinking activities and improve students' mathematical thinking ability. Different students are different due to the diversity of algorithms. The problem-solving strategy, they will use their own methods to solve problems, have a deep experience in solving mathematical problems, and thus gain the experience of learning mathematics, these calculation methods are the results of students based on their own basic knowledge and life experience, each A different algorithm represents an innovative consciousness, which effectively carries out the training of divergent thinking.