Reflections on the Mathematics Teaching of the Generation and Significance of Decimals in the Fourth Grade of Primary School
What is the generation and significance of decimals in Grade Three? A preliminary understanding of the score? And then what? Preliminary understanding of decimals? On the basis of teaching. This lesson requires students to make clear the generation and significance of decimals, the relationship between decimals and fractions, and master the counting unit of decimals and the rate of series between two adjacent counting units, so as to have a clearer understanding of the concept of decimals.
I will teach this class at three levels. First, according to the problems in real life? When the unit of measuring length is not enough to be an integer centimeter, decimeter or meter, how to make students understand the essential meaning of decimals and the relationship between fractions and decimals on the basis of understanding the meaning of fractions. The second step is to make use of the rewriting of meters and decimeters, centimeters and millimeters in the teaching of decimal meaning, so that students can understand the meaning of decimal. Designed? Divide one meter into 10. How much is each part? (1 decimeter) If the unit is meters, how many meters is each meter? Can it be expressed in fractions and decimals respectively? (one tenth), the parents' score is 10, which can be expressed as a decimal, that is, 0. 1. In my teaching, I directly start with the line chart, which is divided into 10, 100 and 1000 on average, so that students can understand the meaning of the score by changing the denominator of 10 and 1000. Therefore, it is avoided that the meaning is not clear enough after adding rice in the textbook. The third level of teaching is mainly through the observation, discussion and review of integer counting units, so that students can expand the progress between decimal counting units and counting units. Make knowledge form a complete knowledge structure system.
Through the above three parts of teaching, the predetermined teaching objectives have been basically achieved.
The disadvantage is that there is no complete numerical sequence table for learning decimals, so it is not clear how many counting units each digit consists of, so we should step up our study and improvement in the next class.
Reflections on Mathematics Teaching of Decimal Reading and Writing in the Fourth Grade of Primary School
This lesson is based on students' mastery of the pronunciation of integers and the meaning of decimals. Reflecting on the teaching of this class, there are both satisfactory places and obvious shortcomings.
The following points are better: 1, concise import, straight to the point. ? I learned how to read and write integers, and now I
Let's summarize the reading and writing of integers. Today, we will learn how to read and write decimals. This has a clear purpose and a simple introduction. 2. Understanding the order of decimal places is the basis of correct reading and writing. First of all, I ask students to find the decimals around them and write these really meaningful decimals on the blackboard, so that students can find the structural characteristics of decimals. When students find that decimals are divided into integer parts and decimal parts by decimal points, they are required to migrate from the numerical order of integers to the numerical order of decimal parts, thus completing the transformation of old and new knowledge. 3. List the decimals around you: the height, thickness and weight of ancient coins that students are interested in, and cultivate students' ability to discover and summarize with knowledge transfer.
But there are also some shortcomings: the relationship between decimal places needs further explanation. For students below the average level, the effect is not good, and further counseling is needed after class, paying attention to every student. In addition, some students are prone to make mistakes in zero reading and writing, so pay more attention.
Reflections on the Mathematics Teaching of the Nature of Decimals in the Fourth Grade of Primary School
The understanding and application of the nature of decimals is the teaching focus of this class. When teaching this section, there is no direct example of 1, but first write 1, 10, 100 on the blackboard. Q: What symbols can be used to connect them? Create such an inspiring, interesting and challenging problem situation to attract students and stimulate their strong desire to explore. They all use their brains and are eager to try. Through everyone's answers and the teacher's guidance, new lessons are introduced unconsciously, which is natural and smooth.
Then, let the students discuss in groups, and draw a conclusion: 1 decimeter = 10 cm = 100 mm. Then ask questions: 0. 1 m, 0. 10 m, 0. The students immediately divided their work and cooperated, and soon came to the conclusion that 1 decimeter =0. 1 meter, 10cm =0. 10 meter, 100 mm =0. 100 meter. Here I have infiltrated the idea of equivalent substitution, and it is not difficult for students to come to the conclusion that 0.1.10m0.100m are equal. Students not only quickly summed up the nature of decimals, but also made them clear about the formation process of this knowledge.
Finally, when practicing, I listed two kinds of problems that often appear in the nature of decimals. Simplified decimals? And then what? Overwrite decimal places? The students have a good grasp. Some students also think that the ending can only be in the sky or a zero should be removed and should be modified.
Reflections on the Mathematics Teaching of the Comparison of Decimals in the Fourth Grade of Primary School
The content taught today is relatively simple. Considering that the students in my class are a little impetuous recently, I didn't design according to the examples in the book, but created a teaching situation by myself: the average score of long jump in our four classes in grade four in last year's sports meeting is as follows ... Please discuss your competition ranking. Because students are very interested in their rankings, they quickly integrate into the atmosphere of discussion.
Combined with the comparison of large numbers learned in grade four, the students quickly discussed the methods of comparing decimal sizes: first compare the integer part, then compare the decimal part; The decimal part should be compared from the high place. When the numbers on the same digit are the same, the method of comparing the lower digits in turn can be basically mastered. There are two problems in students' homework: 1. When the decimal places are different, they are mistaken because of carelessness and rushing for time; 2. For the same number, when the decimal places of the number order change, it is more likely to make mistakes. These two points remind me that how much knowledge students learn depends not only on their ability to accept knowledge, but also on their study habits. Therefore, this is a problem that teachers can't ignore.
Reflections on Mathematics Teaching of Decimal Point Movement Law in the Fourth Grade of Primary School
The movement of decimal point is the key and difficult content of this unit. Just that day, the school invited Mr. Guo to guide our school's mathematics teaching, and Mr. Guo just listened to my class. After listening to teacher Guo's evaluation, I benefited a lot.
The first is teaching material analysis. I remember listening to Mr. Guo twice, and he always put the analysis of teaching materials first. Therefore, it is particularly important for teachers to analyze teaching materials. What I haven't done enough here is to underestimate the difficulty of textbook knowledge, students' practice is not in place, and there are too few problems left after class.
In response to Mr. Guo's suggestion, I have made the following thoughts on the teaching of this course: the better way is to get straight to the point, connect with reality and mobilize the enthusiasm of students; In the classroom, teachers design and involve a wide range of knowledge points, and have a comprehensive grasp of the types of questions and error-prone knowledge points. There are some shortcomings: 1. The whole class is going on, the teacher doesn't catch everyone's attention well, and the students' participation is not enough (which is also the disadvantage of my teaching); 2. The time for students to explore independently, study in groups and think independently is too short, and the time for teachers to teach is too long, which is not conducive to students to acquire knowledge through self-study. The best way to learn knowledge is for students to discover it themselves, because through the knowledge discovered by students themselves, students can understand it most profoundly and easily. Teachers should let students understand for themselves. 3. It is not enough to practice. In the whole class, I pay more attention to students' summing up the law of decimal size change caused by decimal point movement, while ignoring the practice is also an essential part, especially what to do if the decimal point moves left or right when there are not enough digits (it should be to add zeros at the beginning or end, students are prone to make mistakes when adding a few zeros, and the decimal point and the beginning zeros should be removed after becoming integers, but the teacher did not elaborate). Practice is an indispensable part of mathematics teaching, so we should pay more attention to it in future teaching.
The next lesson is the reverse application of the law of decimal point movement, that is, judging the movement of decimal point according to the multiple (fraction) corresponding to the expansion or contraction of decimal point. Students can easily understand this point, that is, according to the decimal point to expand or shrink the corresponding multiple (a fraction) to correspond to the movement of the decimal point, which is time-consuming and easy to make mistakes.
In a word, I think a teacher must fully explore and grasp his role, and don't overstep his authority or break it up too much. It is really a subject that needs to be studied.