What is the math ratio in the first grade of primary school?
Today I talked about the sixth example. How much is it? The topic is xiaohuatao 12 laps, xiaoxue tao 7 laps, how many laps is xiaohuatao more than xiaoxue? The focus of this lesson is: 1. How many sets of small flowers are there than light snow? How many sets is Xiaoxue less than Xiaohua? "Such a question can be formulated correctly. 2. How many sets do you know about Xiaohua than Xiaoxue? It's just that Xiaoxue is not as sleepy as Xiaohua. . It is difficult to understand that the reduced part is the same as that of the two groups. First, the general process of this lesson is: 1, review. Choose some pictures from last semester's Compare How Much to awaken the students' known experience. Teaching space: Select three typical exercises to let students reproduce comparative knowledge and methods in their minds. 2. Newly awarded. The key breakthrough is "How much more Xiaohua is than Xiaoxue?" This question. By swinging the magnetic buckle, we can find out the same part of Xiaoxue in Obana, separate it with dotted lines, and then find out the part with more flowers than Xiaoxue. Let the students try to form and say the meaning of each number. Make it clear that Xiaohua has five sets more than Xiaoxue, and then ask, "How many sets is Xiaoxue less than Xiaohua?" And "What's the difference between the circles in the small flower snow cover?" Teaching space: Let students find out the same part of Xiaoxue in Obana and the part with more flowers than Xiaoxue, and try to make a formula and tell the meaning of the formula. 3. Consolidate the exercises. Do it and ask questions 5, 7 and 9 on page 23. Teaching space: Choose three exercises and one question. Let students consolidate their knowledge in full practice. Second, after-class reflection: In the teaching of this class, students learn more solidly and can basically answer correctly in columns. Only a few students make mistakes when there are three conditions in question 9 on page 23. However, there are still many areas to be improved in the design of teaching space and the level of exercises: (1) Teachers should be good at using questions, questions and questions to arouse students' thinking and expression. Students are the masters of the classroom. How to motivate them to study actively? This requires each of our teachers to think. In math class, we should be good at using questions, questions and cross-examination to arouse students' thinking and expression. For example, in the review part, my operation in class is: What is the ratio of pigs to apples? Look, a pig corresponds to an apple, and each pig corresponds to an apple. What about pigs and apples? Such guidance leaves students with little teaching space. When discussing with Director Han, Director Han reminded me that since we are reviewing old knowledge here, we should first give students more space for independent observation, and then ask "Who is this?" What did you find? "The effect of asking questions, questioning and rhetorical questions is definitely much higher than that of telling. For another example, when I showed the magnetic buckle and compared the parts with the same number of rings in the Obana snow cover, I asked, "How many parts does Xiaohua have?" One student quickly said, "Seven." I immediately asked, "You didn't count, how do you know it was seven?" She said, "Because this is the same part of Xiaoxue in Obana, Xiaoxue has 7 on its cover, and this part of Xiaohua is also 7. "The questions here are very valuable, and students can shift their attention from simply focusing on numbers to the fact that this is the same part of Obana Xiaoxue. Timely questioning, questioning and rhetorical questions are like a small stone. Although it is "small", it can arouse "a thousand waves"! (2) Pay attention to the design of exercises, and the selection and presentation of exercises in class should be targeted and hierarchical. In this lesson, I chose four exercises (doing one thing and questions 5, 7 and 9 on page 23), all of which revolve around the practical problem of "how much to compare" The pertinence is very good, but the hierarchical design is slightly insufficient. After class, I think it would be better if the presentation of the exercises could be changed to the following design: 1, do it. The correct formulation. Let students be primary school teachers. What do you mean by 15? What does 9 mean? 2, page 23, question 5, you can ask again, "How many boxes were picked up in the afternoon than in the morning? How many boxes are there between morning and afternoon? "On page 23, question 7, you can show two bees first and let the students tell what they know. Can you ask some math questions? First show two conditions for students to ask questions, which can reduce the difficulty and cultivate students' ability to observe, analyze, understand and ask questions. Question 9 on page 23 (there are three conditions) also shows the conditions first. The teacher asked a question and asked the students to ask different questions. Compared with question 7, this presents another difficulty.