Tisch
"Standard" points out that mathematics teaching should be the teaching of mathematics activities, emphasizing strengthening students' experience and emphasizing that students should learn valuable mathematics. This lesson is based on students' preliminary understanding of the meaning of multiplication, and they can use the multiplication formula of 2-5 to calculate the multiplication in the table. The main goal of this lesson is to let students experience the process from "random grading" to "average grading" through practical operation (that is, the practice of marking one point), understand the meaning of average grading, average some specific items according to requirements, and know how many copies each is. Reflecting on this lesson, I think there are the following gains and shortcomings. 1. Create problem situations to stimulate students' curiosity and make them happy to engage in mathematics learning activities.
At the beginning of this class, I asked a story-telling question: How many ways does a mother monkey give her two baby monkeys all eight peaches? Please use round blocks instead of peaches to divide one point (students are willing to divide it by hand). List all kinds of points through class communication. Then ask: What kind of division do you think will satisfy both baby monkeys? Speak your mind. Every little monkey gets the same number of peaches.
2. Let students learn mathematics in vivid and concrete operation activities and experience the meaning of average score.
Piaget, an educational psychologist, believes that cognition does not occur in subject or object, but in the activities between subject and object. The understanding of "average score" is the beginning for primary school students to learn division. In teaching, in order to let students understand the meaning of "average score", I guide students to participate in various forms of "one score" activities and follow suit, from two to more, from "random score" to "average score". In the process of participating in these operations, it not only stimulates students' interest, but also helps students to experience and understand mathematical knowledge, that is, the understanding of "average score".
3. Conduct effective group cooperation and communication, and feel the diversity of sub-methods and the unity of answers.
In the activity of "Kittens Divide Fish", I asked my classmates to cooperate and help kittens solve the problem of "12 fish". Four kittens want to share the same amount of fish. How many fish does each kitten get? "Four students in the group play four kittens respectively, and use 12 sticks instead of fish. After dividing, send representatives to report how they divided (that is, exchanging points and saying different ideas) and what results they got. The diversity of sensory points and the unity of answers. This not only respects the differences of students' life experience and cognitive characteristics, but also provides a broader space for students to show their personality and let different students develop differently in mathematics. Then guide the students to show the process and result of fish division in pictures.
In a word, this lesson has accomplished the teaching task well. The disadvantage is that students' language expression ability needs to be further improved. Strive to foster strengths and avoid weaknesses in the future teaching process and strive to become an excellent math teacher.
extreme
"Peach-splitting" is taught on the basis that students have mastered the oral calculation of multiplying one digit by two digits, two digits or three digits by one digit within 100. In this section, we learned that the quotient of two (three) numbers divided by one number is the written division of two (three) numbers; This part is the basis of further research.
Playback teaching process: After introducing scenarios, students are required to calculate 48÷2 in different ways. Students' oral calculation results are easy, but they can't correctly understand and calculate the vertical form. Some students have several ways of writing when trying to calculate the vertical position, but these mistakes appear repeatedly in the later classes, which are very stubborn and make me have a headache.
Error analysis: A few students don't understand this kind of vertical abstract writing, and they don't understand and are unfamiliar with its process and writing order. This is a mechanical imitation.
Reflective teaching.
(1) Linking concrete operations with abstract formulas in the teaching process can help students understand arithmetic on the one hand; On the other hand, it can help students build mathematical models to solve problems. Teachers should pay attention to guiding students to understand the order of pen division in arithmetic: when we split peaches for the first time, we divided peaches into four baskets, and each monkey got two baskets. In the vertical form, we divide four tens by two to get two tens, write two on the tenth of the quotient, multiply the two tens by two, and the product is four tens, and write four below the tenth of 48. Divide it into eight parts. In vertical form, 8 will fall and continue to differentiate. Eight divided by two makes four. Each monkey will get 4 pounds. Write 4 in the quotient unit, and then multiply 4 by the divisor 2. The product is 8, which means that the dividend is divided by 8. Write it under the falling dividend 8. Subtracting 8 from 8 to get 0 means everything.
(2) After students solve problems and master algorithms, they can be guided to induce, compare and question, which can cultivate students' reflective ability and find solutions to problems. Teachers guide students to realize that when using vertical calculation, we should pay attention to whether there is a remainder in the tenth place after the first quotient, and combine this remainder with the number in the unit before calculation. The remainder must be less than the divisor. Timely induction: when calculating with a pen, divide the dividend one by one, and the quotient is written on the dividend one by one. Here, students can use a favorite Song formula to remember that divisor is the rule of single-digit pen division: pen division starts from a high position, except one quotient and one quotient, and only one quotient can be divided at a time. And in the future study, I will continue to add the following lyrics: "One is not enough to see two." "Not enough quotient 1, 0 takes up space".
(3) Practice repeatedly and slow down the progress. According to the intention of the textbook editor, the above content is completed in one class, but I think this content is suitable for two classes and can be divided into content and objectives. The first class only studies the quotient of two digits divided by one digit. The key point is to let students master the writing method of vertical calculation, the meaning and process of each step, the difference between vertical calculation of division and vertical calculation of addition, subtraction, multiplication and division. In the second class, we will learn three digits divided by one digit to get the quotient of three digits. The key and difficult point is to let students master the processing method that the first quotient has a remainder after ten digits in vertical calculation, and to be further familiar with the order and process of pen division.
(4) Before class, review the writing format of multiplication formula, oral division, vertical division and the meaning of each step, which is the learning basis of this lesson and helps to understand the vertical division of this lesson. For example, before class, let students calculate 9÷2 18÷5 vertically, and let students answer the meaning of each step. 15 Where did this 15 come from? What does this mean?
How did this 3 come from? What does this mean?
(5) In this class, while focusing on algorithm optimization, should we highlight the diversity of algorithms and pay attention to guiding students to explore? But 40 minutes in class is too short, leaving little time for students to practice. How to solve these contradictions is a problem that I have been thinking about.
Tisso
In the course of teaching peaches, use remote resources to create the following scenarios.
1. Question situation, make full use of the situation provided by audio-visual media and teaching materials to carry out teaching activities. Throughout the teaching activities of this class, I have created a number of mathematical situations, which not only effectively enliven the classroom atmosphere, but also stimulate students' interest in learning; Moreover, taking the image scene as the medium shortens the distance between image thinking and abstract cognition in the cognitive process of primary school students. For example, from the beginning, playing with the mother monkey to give two monkeys eight peaches, it expanded to how to give two monkeys six small red flowers, and then expanded to how to divide six small red flowers equally among five children, creating a math game of "trying to divide 12 children equally", which filled the whole class with interest, made students understand that mathematics originated from life and was used in life, so that students felt cordial and found problems in their research.
2. Cultivate students' practical ability and thinking ability.
In this lesson, students can experience the process of acquiring knowledge through hands-on operations (such as dividing points, placing positions, filling, circling, drawing, etc.). ), I gradually realized what "as much", "as much" and "average score" mean. At the same time, in the teaching of this course, I not only pay attention to the results of students' "average score", but also pay attention to guiding students to explore the differences of "average score", so that students can experience the diversity of problem-solving strategies, further develop students' thinking ability and hands-on operation ability, stimulate students' interest in learning, enhance students' confidence in learning mathematics well, promote students' all-round, sustained and harmonious development, and help cultivate students' innovative spirit.
3. Guide students to think independently and cooperate and communicate.
In this class, we carry out math learning activities in the form of group cooperation, so that students can explore the method of average score through mutual exploration and communication. In teaching, I participate in students' group activities as a collaborator and instructor. In the teaching process, I pay attention to respecting and appreciating every student, and students actively express their unique ideas, so that students can communicate with their peers and listen to their different views; Pay attention to students' expression, understand students' learning trends in time, guide them, inspire students to explore the meaning of average score, and create a good learning atmosphere for students.
In a word, I not only pay attention to the feeling process of knowledge, but also pay attention to the emotional education of students in class. Students' listening ability needs constant training.