Reflection on Mathematics Teaching in Senior Three: Model: Oral Calculation
"Division by Oral Calculation" is the teaching content of Unit 2 in Volume 2 of Grade Three of People's Education Press. It is taught on the basis that students have mastered the multiplication and division in the table and the multiplication of one digit and multiple digits, which lays a solid knowledge and thinking foundation for the following students to master the division and division of two digits and multiple digits. As the beginning of this unit, how to make children understand the arithmetic of division is both important and difficult.
According to past experience, students can quickly grasp the law of calculation, but they can only understand the process of calculation, or they can't describe it completely and orderly in words. However, in this book published by New People's Education, many contents focus on letting children explore the process of calculation, rather than blindly pursuing results, which is a great challenge to our teaching.
Before this class, I thought for a long time, how to make children interested in exploring arithmetic in class, and how to make children naturally understand the truth of division calculation? Around these, I made some detailed preparations, and then found that it was these small details that made the children quickly enter the state, thus successfully completing the learning task.
Before teaching the example 1, I asked the children to count 100 pieces of handmade paper and asked: How to count 100 pieces of handmade paper quickly? Soon, some children found that the number of sheets 100 was too slow, so some students raised their hands and asked, teacher, can you divide these papers into piles 10, so that it can count 10. Everyone thought it was a good idea, so I tied 100 pieces of handmade paper into 10 pile, and asked: If you count one piece at a time, how many pieces are there in 100? If the number of piles is 100, how many are there? The children immediately reflected that the counting unit changed from "one" to "ten", so the counting speed was accelerated. Then I asked: How to count 40 pieces of handmade paper quickly? At this time, many children choose one by one. Asked why, the children proudly told me with data: if one piece counts 40 times, if ten pieces count only 4 times, it can save 36 times. So I used the children's understanding to introduce it into this class, explaining that since it is verbal calculation, it is necessary to reflect quick calculation, so how to save trouble is the focus of this class. In this way, it is more natural to enter the transition of example 1, and at the same time, children's understanding that adding "0" to the cover is actually changing the counting unit is solved.
Through the attempt of this class, I fully feel that teachers can only give students more time in class, let them feel, communicate and learn by themselves, and gain new knowledge through their own efforts, so as to improve students' autonomous learning ability and better complete teaching tasks.
Reflection on Mathematics Teaching in Grade Three: Fan: Sorting out Schoolbags
Sorting out schoolbags is mainly to let students go through the process of classification and learn to classify according to certain standards or user-defined standards. Get into the habit of organizing things in an orderly way. Realize that there is mathematics everywhere in life. In order to achieve this goal, I did the following two things.
1, let students experience the classified activities.
In teaching, according to the reality of students, the requirements of sorting out schoolbags are put forward. Please take out the things in your schoolbag and tidy them up, and talk about how to tidy them up in the group. The design of this link aims at teaching in connection with students' real life, which is helpful for students to determine the classification standard in hands-on operation. At the same time, let students feel that when solving the problems around them, they must classify the goods according to certain standards.
2. The mathematical thought of infiltration classification.
In life. Classification is an intuitive process of rearranging items with the same characteristics, while classification in mathematics is an abstraction and process of reclassifying concepts according to certain characteristics. In order to let students understand the idea of mathematical classification, starting from the familiar living environment of students, the requirements of sorting out schoolbags are put forward. Because sorting out the items in the schoolbag is concrete and intuitive, students can divide their school supplies into three or four categories, and talk about the reasons for this classification. Why are there so many ways of organization? Let the students experience classification in practical activities, and let them know the classification method in the process of playing. Combine study and life closely, and further feel the method of object classification.
Reflection on Mathematics Teaching in Grade Three: Quality Unit
"Kilogram" and "gram" are the mass units that students first come into contact with. Although students often have to deal with them in daily life and feel the weight of objects, they lack understanding of the unit of mass. Because the unit of quality is not as intuitive as the unit of length, especially for students who have just entered the third grade, they pay more attention to its surface characteristics such as size and length, and pay less attention to the weight of quality. How to let students establish the quality concept of 1 kg? Teaching experience tells me that children's acceptance of knowledge must be a process from perceptual to rational, and this process must have been experienced, not replaced by teachers. The unit of mass is not as intuitive as the unit of length, and it cannot be understood only by observation. Let students feel the weight of 1 kg in specific life situations and operational activities. But there is no scale in kilograms in the school. Teachers borrow them all by themselves, let alone one in a group. So, I arrange for students to preview before class:
(1) Go to the supermarket to find out which items weigh 1 kg and weigh them by hand.
(2) Go to the market to buy food with my mother on Sunday, and see what my mother bought, each weighing several kilograms. Help mom carry it again and see how many kilograms you can carry. I also prepared in advance: two bags of salt (500g each), one bag of washing powder 1kg, apples 1kg, dates 1kg, eggs 1kg, etc. Let the students communicate in class which items in the supermarket weigh 1kg, and then take out all kinds of 1kg items I prepared in advance for the students to weigh in their hands. Students really feel the actual weight of 1kg through practice, operation and other activities and their own experiences. At the same time, I feel that the weight can't just depend on the size of the package. Make students realize that they are the discoverers, researchers and explorers of learning activities, and really stimulate their strong interest in learning mathematics and become the masters of learning activities.
Students can solve the problems in this unit because the content is relatively simple and students can basically answer them. What other questions can you ask? Some students' narratives are incomplete. When filling in the company name, I ask students to think about whether their filling is reasonable in real life, which is more effective. The knowledge of estimating the weight of objects is relatively weak, because students need to accumulate certain life experience, master certain methods, find out the heaviest, then the lightest, and then compare the remaining items. Due to students' lack of life experience, it is difficult to complete such topics.
Reflections on Mathematics Teaching in Grade Three Fan Siwen: Buying New Books
This lesson is the content of the fourth section of Unit 6 Division in the first volume of the third grade of the primary school mathematics textbook published by Beijing Normal University. It is a mixed operation of continuous division and multiplication and division after students learn and master the division of two digits divided by one digit and three digits divided by one digit. The textbook provides a situation of "buying new books", that is, understanding the quantitative relationship of continuous division application problems and the operation order of continuous division, multiplication and division mixed problems in the process of solving problems. The purpose of arranging teaching materials in this way is to understand the operation order in actual needs, not to impose it on students. I hope students can realize that mathematics comes from the real life around them and return to real life to solve problems. After practical teaching, I have the following reflections:
1. The content of buying a new book has both mixed operation and quantitative relationship. When I teach, the focus is on the understanding of quantitative relations. I think it is a little difficult for me to arrange the teaching content of this course. Therefore, students may not be able to keep up when they master the quantitative relationship of application problems and the operation order of mixed operations. Then in the future study, I will also practice the operation order of division and multiplication and division.
2. It is difficult for students to understand the quantitative relationship. First, students can think independently, so that they have enough time to think. Then, with the help of the intuitive demonstration of courseware and the significance of multiplication and division, they can get the idea of solving problems and reduce the difficulty.
3. In order to make students have the desire and interest to solve problems and stimulate students' problem-solving strategies, I changed the teaching method of single application problem in the past. In practice, forms include calculation, choosing one, telling the meaning of the formula, and having extra information to solve the problem. Stimulated students' interest and made them solve one math problem after another in an excited state.
Reflections on Mathematics Teaching in Grade Three: A Preliminary Understanding of Decimals
"Preliminary understanding of decimals" is the teaching content of Unit 7 of Book 6. Children usually have the experience of shopping in supermarkets, and they are no strangers to decimals representing prices, so I put the focus of this lesson on reading decimals and teaching the meaning of decimals representing length. In the presentation of content, students are familiar with daily affairs and life, and intuitive and semi-intuitive models such as RMB and number axis are used to help students understand decimals initially and solve simple practical problems. In the teaching of this class, I try to do the following:
First, closely combine life situations, so that students can understand the meaning of decimals in concrete practice.
In the teaching process of understanding decimals, I first asked my classmates to talk about decimals they saw in their lives. Students are very observant and talk about many decimals in their lives, which are related to life. Students quickly participate in the classroom, thus well stimulating students' interest in learning. After reading decimals, students will return to life again and talk about decimals in life. I also choose to let students read decimals in life and pay attention to their expressions in specific situations. Make full use of students' life experience and existing talents, activate students' relevant experience and knowledge base, guide students to understand the meaning of decimals in many expressions, and promote the positive transfer of learning.
Second, give students the opportunity to think and solve problems independently, and pay attention to children's cooperation and communication.
When trying to read decimals and summarize decimals, I ask students to try reading first. After reading many decimals, ask the students to sum up their decimal readings, first in the group and then in the class. When teaching why one meter and three minutes is 1.3m, I also let the students think independently first, and then cooperate and communicate. By dividing 1m into 10, students can construct the relationship between decimals and fractions independently. Through guessing, giving examples, verifying, exploring independently and cooperating, students can understand decimals and understand their meanings. After learning the example 1, let the students finish "doing one thing" independently, which will help each student to feel and understand the specific meaning of decimal representation through peer exchange, and help students to learn actively and learn to learn. Through reading, thinking, discussing and speaking, this class enables students to participate in the learning process with their hands, mouths and brains, creating a relaxed and harmonious classroom atmosphere for students and changing "I want to learn" into "I want to learn".
In this class, I also feel a lot of shortcomings: although I try my best to make students learn more independently in this class, sometimes when students can't say it, they will rush to say it, which is not enough. For example, in teaching1.3m, why1.3m? The students have understood that the organizational language is not in place. I will lead the students to say it again. There is also the "do-and-do" teaching. Through the previous study, the students have understood the relationship between decimals and fractions and got this question right, but I am still afraid that the students will not understand and explain a lot of things. In this way, the time to consolidate the practice can't keep up with the time.
In short, this class made me deeply realize that students' lives are rich and they are very good at observing life. Teachers should take students' lives as valuable resources, make full use of them, and guide new knowledge through existing cognition. In the classroom, the study time, space and exhibition opportunities are reserved for students. Only through discussion and communication between teachers, students and students can we improve teaching efficiency and enhance teaching effect.