Current location - Training Enrollment Network - Mathematics courses - Reflections on practical problems in teaching with closed lines and question marks
Reflections on practical problems in teaching with closed lines and question marks
The teaching content of this lesson is to solve practical problems represented by closed straight lines and question marks in the form of pictures, mainly to let students understand the structure of practical problems of addition and subtraction, that is, two known conditions and one problem, and then learn to determine the algorithm according to the relationship between known conditions and the problems to be solved.

Although the content of this lesson is not much, there are only two knowledge points. But after all, it is a new lesson, and students are in contact for the first time. Moreover, for students, especially junior students, their acceptance of new knowledge mainly depends on their first acceptance and understanding of information. If students fail to grasp the main points and explain clearly in the first explanation, they will often spend more time on counseling and counseling, and sometimes it is difficult to completely correct them. Therefore, when teaching new knowledge, I am in no hurry to achieve success. First, I draw a picture (three apples on the left and five apples on the right) for students to observe and describe in words. Then guide the children to look at the pictures and ask a question calculated by addition.

Because the students have learned to solve the problems of figures and words by addition, they quickly asked, "How many apples are there on the left and right?" There are several words in this question. It takes a while to write it down, but the' symbol family' in the mathematical kingdom can help us solve this problem. You can use this symbol to express it (with calligraphy and painting on the blackboard). Let the students look at this symbol and talk about its meaning. When asking several children what they mean, some children say that they mean to combine the left and right sides into a * * *, but they also hear some children say that they are asking "a * * * *". His statement certainly represents the thoughts of some children in the class. This is exactly what I am worried about the mistakes my children will make when they do problems in the future, and it is also the answer I hope to hear in this class. Only when children's mistakes are found in the classroom at the first time can they help children solve problems and eliminate learning obstacles in time, because students are not deeply impressed by mistakes when they are beginners, and it is easy to eliminate wrong views and opinions. I didn't categorically deny the student's answer, but told him, "It's not that capable. It means combining left and right, which means * * *. You see, it surrounds the left and right things with its left and right hands and closes them up. " I visualized the meaning of the outline in an anthropomorphic way, and the students nodded, which made sense. Just add a "?" Under the closed line. (blackboard writing? ) I just expressed that question. Who can tell me what the question mark here means? Then ask the students to compare the symbols on the blackboard, make clear the meaning of the symbols and realize the benefits of the symbols. After teaching this example, I didn't teach "give it a try" immediately, but asked the students to "give it a try" with their hands and brains and think 1 and 2. Organize students to look at the picture first, and talk about the known conditions and requirements at the same table. Then the whole class communicates clearly the meaning of the picture and the questions to be asked, and then let the students answer in a row. The purpose of doing this is to let students internalize knowledge in the process of oral English and promote students' understanding and mastery.

Then I teach "give it a try". In teaching, I show the whole picture directly, so that students can carefully observe the meaning of the circled line in the topic, including the meaning of "10" below the circled line; And "?" Where it is and what it means. On this basis, let the students say two known conditions and one question about this problem. I am more open in this session, so that students can analyze the structure of practical problems and make their own statements.

After that, I organized students to observe the two pictures on the blackboard again and compare them: What are the similarities and differences between the two pictures? Students found that the lines enclosed in the picture all indicate that the left and right sides are combined into a * * *, and they all have "?" At least one of the left side and the right side is a known condition; The difference is "?" Different positions mean different problems to be solved and different methods to solve them. How much is under the circled line? Find a * * * to solve by addition. "?" The one on the left or right is a part of the total, which should be solved by subtraction. Students experience the pleasure of "discovery" in comparative exploration, thus achieving teaching objectives and improving classroom quality.