Divide the number 4 into 3 and 1, 2 and 2, 1 and 3; Think about it? How many plus how many equals four? . The first step of teaching is opening up, and each student has his own way to put it. There are three different ways to put it in communication. The communication here, on the one hand, shows that the release methods are diverse and many possible release methods have been found. The next step is the teaching reflection on the division and combination of mathematics brought by learning. I hope you like it. ? Reflections on the teaching of dividing and combining mathematics? ( 1) ? Integral? With what? Close? It is two aspects of number composition and an important basis for adding and subtracting numbers within 10. Most students like to learn from? Close? Sum from the point of view of … and calculate the subtraction from …? Integral? The angle of difference. Teaching materials guide students to master gradually? Integral? With what? Close? The relationship. ? (1) composition teaching 4. Know first? Integral? Meet again? Close? , release? Integral? With what? Close? Teaching separately makes it easy to understand the meaning one by one, and initially feels related. ? (2) composition teaching 5. Put forward? Integral? With what? Close? Where do the students come from? Integral? Say it right away? Close? , so that the two become one. ? ③ Questions 33 1 and 2, 36 1 and 37 1. After teaching the decomposition of numbers 6, 7, 8, 9 and 10, practice these numbers on the project? Close? . Use? Integral? Knowledge answer? Close? Problems, experiences? Integral? With what? Close? This goes hand in hand, remember? Integral? , can you say? Close? . ? (2) Except 2, every number from 3 to 10 has two or more decompositions. It is symmetrical to arrange all kinds of decomposition of a number in order. Such as the decomposition of 5:? Mastering this symmetry can improve learning efficiency and reduce memory burden. The textbook guides students to understand and apply this symmetry step by step. ? ① The composition of teaching 4, although 4 is divided into 3 and 1, 2 and 2, 1 and 3 are symmetrical, but considering the composition of the preliminary teaching number, the emphasis should be on understanding? Integral? With what? Close? The meaning of learning and the composition of the number of learning activities do not reveal this symmetry for the time being. ? (2) The composition of Teaching 5, through two students' observation of the same five flowers divided into 1 and four flowers in different positions, I realized that 54 1 and 5 14 are the same, and they are essentially two expressions of a group decomposition. Then let the students look at the pictures of five flowers arranged into two and three flowers, and write two representations of this group of decomposition. The textbook draws a dotted box on one expression to make students understand that it can be obtained from another expression. ? (3) teach the composition of 6 and 7, and write the decomposition of a group of numbers according to a picture. The expression in the dotted box starts directly from the left. It is enough to feel the composition of 6 and 7 three times, which lays the foundation for improving the composition teaching efficiency of 8, 9 and 10. ? (4) Have the compositions of Teaching 8, 9 and 10 passed? What else can you think of? Guide the students to say the decomposition of these numbers and other numbers. Understand the composition of a larger number, as long as you remember half, you will remember the other half. ? Reflections on the teaching of dividing and combining mathematics? Divide the number 4 into 3 and 1, 2 and 2, 1 and 3; Think about it? How many plus how many equals four? . The first step of teaching is opening up, and each student has his own way to put it. There are three different ways to put it in communication. The communication here, on the one hand, shows that the release methods are diverse and many possible release methods have been found. On the other hand, it provides image support for the composition of students' memory 4. ? 1. Experience division and combination in operation and master the composition of research numbers. ? Understanding the composition of numbers through operation is the teaching strategy of this unit. All examples and? Try it? Everyone divides several objects into two parts first, then decomposes the abstract components of the divided objects into numbers, and then realizes the combination of numbers from the decomposition of numbers. Constantly let students experience the activities of separation and integration, and feel that there are differences and connections between separation and integration. ? On page 30, the composition of Example 4 is divided into three steps. First, put four peaches on two plates, and let the students experience them while operating? Integral? ; Then put three peaches in the four-peach tray and 1 peach in the other tray to get 4 divided by 3 and 1, so that students can understand what 43 1 means and how to get it. Then ask the students to think about what they can get from the separation picture of the middle and right peach blossoms. Semi-independent completion of 4 is divided into 2 and several, and then independent completion of 4 is divided into several and several. What is the third step in teaching? Integral? The basis of reasoning? Close? Because 4 is divided into 3 and 1, 3 and 1 synthesis 4. This example is the first example in this unit. The teaching task is not limited to the composition of 4, but also includes the idea of division and combination and the method of studying the composition of numbers, which is directly related to the teaching of other numbers. Therefore, students must be involved in the activities of splitting peaches and experience the process of solving numbers from the abstract components of objects. ? 2, in the activities of separation and combination, gradually improve the requirements of intellectual activities. ? The division and combination of numbers have certain rules. Finding and applying these laws can improve the efficiency of exploration activities and the level of memorizing numbers. ? ( 1) ? Integral? With what? Close? It is two aspects of number composition and an important basis for adding and subtracting numbers within 10. Most students like to learn from? Close? Sum from the point of view of … and calculate the subtraction from …? Integral? The angle of difference. Teaching materials guide students to master gradually? Integral? With what? Close? The relationship. ? (1) composition teaching 4. Know first? Integral? Meet again? Close? , release? Integral? With what? Close? Teaching separately makes it easy to understand the meaning one by one, and initially feels related. ? (2) composition teaching 5. At the same time? Integral? With what? Close? Where do the students come from? Integral? Say it right away? Close? , so that the two become one. ? Reflections on the teaching of dividing and combining mathematics? Last night, I saw some seniors' reflections on this lesson on the Internet, and I gained a lot. The topic is division and combination, or it is worth remembering. Many times, the teacher only pays attention to the process of division and ignores the process of combination, which is the basis of addition in the next section. Because the students in the class have a weak foundation, I give them this course on a zero basis. Judging from the students' class status and homework, it is better than previous classes. It seems that the first step in preparing lessons is to prepare your own students. ? This course seems simple, but it is actually very hierarchical, which has an impact on the following addition, subtraction, abdication and carry learning. For example, carry addition and ten times ten method are to combine two numbers, and abdication subtraction is to reduce one to ten, then divide ten into two numbers and subtract the number to be subtracted. ? This class does not use courseware, but directly demonstrates on the blackboard with small magnets, and the effect is good. The small magnet is simple and familiar, and the students' attention shifts to the teacher's question. The process of hand-drawing is more vivid and intuitive than courseware, and the teacher draws the blackboard and the students can understand it easily. It can be said that 5 can be divided into 2 and 3, but in mathematics, for simplicity, we use this form to represent the division of 5. This will make it easier for students to understand the division of 5. ? Let students do more homework, use more brains and talk more in class, which can better mobilize students' learning efficiency.

Reflections on the teaching of the division and combination of mathematics;

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