The elapsed time is calculated because students deal with time every day, such as sleeping time, flight time, business hours and so on. Therefore, most classes are guided, and students can understand and calculate the elapsed time in the form of life cases. The teacher left home at 7: 05 and arrived at school at 7: 45. Ask the teacher how long it took from home to school. Simple examples of calculating the elapsed time are also arranged in the textbook, which is not difficult. The examples presented in the book are directly counted on the line segment diagram and clock face, and the conclusion is very intuitive. But in the later exercises, it involves solving problems by mathematical methods, converting all the time into 24-hour timing method and subtracting the start time from the end time. But in the calculation process, with the abdication of multi-digit addition and subtraction, students are prone to make mistakes. Another kind of sleep problem bothers many other students. It is more complicated because it involves cross-day calculation. It can be represented by a line graph. These two moments occur in two days and should be counted in days, so as to teach students to understand and master them easily in future exercises.

In teaching, I also found that students have a vague concept of time and time. These are two different concepts. For example, 5 o'clock is 5 o'clock, which is what we usually say. This is a moment, and five hours in our daily life means five hours have passed, which is a period of time.

With the deepening of students' understanding and practice, I believe students will have a better understanding of such problems, so that time can really penetrate into students' lives and let students really understand time.

Reflections on the second volume of mathematics teaching in the second grade and the third grade of primary school

"Divider" is the division of a digit "1". In the teaching of oral arithmetic, students' independent activities should be emphasized. Students' existing oral calculation experience related to the division of single digits includes: in-table division and oral calculation of single digits multiplied by 10 or 100. These oral calculations are the basis to help students solve the oral calculations with divisor of single digits. Therefore, in teaching, I pay attention to activating students' existing experience, arousing students' memory of old knowledge, and using it flexibly under the new situation that divisor is single digit.

2. Strengthen the teaching of estimation. Estimation is of great significance to the cultivation of students' sense of numbers. In teaching, I try to show students different estimation methods. Let students realize that there are different strategies to solve the same problem, as long as they are reasonable. When estimating the divisor as a single digit, students are required to discuss some general division rules. After allowing students to communicate freely, guide students to summarize the divisor principles of finding dividend: one is close to dividend, and the other is convenient for oral calculation. In the process of inquiry, students realize the significance and function of estimation, thus cultivating their estimation consciousness.

3. In the teaching process of pen division, pay attention to guide students to explore the arithmetic and calculation rules of pen division. In the teaching of written division of labor, vertical writing is a difficult point, and the students' existing experience is not enough at this time. So in teaching, most of the time is spent on solving the order of division and vertical writing. Guide students to express the process of writing in mathematical language. Let them talk to themselves and whisper their own thinking process. Know what to do first, then, finally, when doing pen division, there is a reasonable calculation order.

4. Strengthen the connection of multiplication and division to improve students' simple reasoning ability. When checking the calculation of division in teaching, let students draw the method of checking division by multiplication according to the reciprocal relationship of multiplication and division.

Reflections on mathematics teaching in the second volume of the third grade in the third primary school

This lesson is the first lesson of "Two Numbers Multiply Two Numbers" in Unit 5 of Book 3 of Mathematics published by People's Education Press. It is taught on the basis of oral calculation of integer 10 and integer 100. According to the students' experience and the basic role of this course in this unit teaching, my preset teaching objectives are: try to explore the process of oral calculation, learn to calculate the whole ten, the whole hundred multiplied by the whole ten and the two-digit multiplied by the whole ten and the whole hundred (each product is less than ten); Experience a variety of oral calculation methods, and correct calculation is the key and difficult point. Students' autonomy, cooperation and inquiry are adopted, supplemented by teachers' guidance and centralized teaching, and multimedia is used for teaching. Disadvantages:

1, learn oral arithmetic with the help of practical problems.

Make full use of the corresponding life cases and problem scenarios provided in the teaching materials, such as postman delivering letters, delivering newspapers, and children buying stamps. , create vivid. Situation, let students find and ask mathematical questions, then explore oral calculation methods, and then solve the practical problems. I found that combining the activities of discussing verbal arithmetic with solving practical problems, the learning materials are full of vitality, attractive to students and easy to arouse their interest in learning. At the same time, discussing the method of oral calculation in solving practical problems can make students deeply understand why oral calculation is needed and realize the significance and function of oral calculation. It is advocated in today's mathematics teaching to integrate mathematics learning into real situations. As a teacher, we must realize this and work hard.

2. Guide students to actively explore oral calculation methods.

It is one of the important reform ideas advocated by the new curriculum standards to let students experience the formation of knowledge. In this teaching, I preset the learning situation of students' autonomy, cooperation and discussion, aiming to let students explore new oral calculation methods by using existing knowledge and existing oral calculation methods. On the basis of students' independent exploration, organize discussions and exchanges in time, improve students' understanding of oral calculation process and reasoning, gradually learn to solve problems with mathematics, and gain a successful experience. In classroom teaching, students can actively participate in learning, but they are not very good at transferring and using according to their inherent experience, and the expression of oral calculation method is not accurate enough. In this regard, although I corrected the students in time, the effect was not obvious. It can be seen that in this respect, I still need to strengthen my study and exercise in order to give students guidance and guidance.

3. Advocate and encourage the diversification of oral calculation methods.

In teaching design, I advocate students to use and experience a variety of oral calculation methods, but in actual teaching, I found that most students' methods are relatively simple, and after my guidance, I did not see good results. After class, I deeply think that all the students in this class have learned the content of this section, which should be because of the teacher's emphasis: when multiplying two factors, you can multiply the number before 0 first, then look at how many zeros there are at the end of the two factors, and add a few zeros at the end of the product. This also inspires me that in teaching, we should pay attention to developing students' multi-angle thinking, encourage students to use different methods to solve problems, and cultivate students' ability to "choose the method suitable for practical problems" through comparison and communication, so as to develop students' sense of numbers instead of simply teaching.

Reflections on mathematics teaching in the second volume of the third grade in the fourth primary school

The teaching goal of "Multiplying even numbers" is to achieve the following points in knowledge and skills, mathematical thinking, problem solving, emotion and experience:

1. Understand and master the calculation method of two-digit numbers in actual situations, and be able to calculate correctly and skillfully.

2. In the inquiry algorithm, let students communicate with others, enjoy the happiness of expressing their opinions after independent thinking, and get a successful experience.

3, can apply knowledge to solve practical problems related to life, understand the role of mathematics, and initially establish the awareness of applied mathematics.

4. Let students understand the close relationship between mathematics and human society, understand the value of mathematics, and enhance their understanding of mathematics and confidence in learning mathematics well.

The key point of this lesson: master the written calculation of multiplying two digits by two digits. The key is that students can master the order of multiplication and the number of digits of two products.

Reflections on Mathematics Teaching in the Second Volume of Grade 5 and 3.

Every time I finish an open class, I feel a lot. After the "24-hour time method" class, look at the performance of the students and the exam results. I feel that the effect is not very ideal. Looking back on the whole lesson preparation process, there are successes and shortcomings. First, from the teaching focus, the effect is good.

The focus of teaching is quite accurate. The key point of this lesson is to let students understand and discover the connection and difference between the ordinary timing method and the 24-hour timing method, and correctly exchange the time expressed by the 24-hour timing method with the time expressed by the ordinary timing method. At this point, I grasp the key points, carry out teaching, draw conclusions by students, and give full play to students' team cooperation spirit and inquiry ability.

Second, from the design of exercises, it is clever and open.

An exercise, changeable, step by step, from shallow to deep, and diverse solutions, gives students a space for creation and divergence. Moreover, the exchange of two timing methods from the preview list of programs that students are interested in not only consolidates the knowledge they have learned, but also cultivates students' sense of cooperation. In addition, in the evaluation, I also did this well, and I was able to give proper evaluation in time, which also stimulated students' enthusiasm and interest in learning.

This class also has some shortcomings. As soon as I finished, I felt that the effect was not good. I never seem to be in the mood. The students' discipline is very good, but they are very serious, which makes the learning atmosphere of the whole class very tense, making it difficult for students to learn, and the effect is also affected. From the perspective of preparing lessons, students are not fully prepared. There are still some difficulties for students to understand the 24-hour timing method, and they can't quickly distinguish the 24-hour timing method from the ordinary timing method. In this link, I should practice more and give full play to my teaching wit, so that students can master it well, but I can't. In this regard, I will work harder and constantly reflect on my own shortcomings.

In a word, this class has gained a lot. According to my own reflection, I revised the lesson plan and made up the difficulties for my classmates after class. In the future teaching process, I should know more about students and pay attention to them. Let students accept knowledge well in class, thus improving teaching quality.