Opening remarks: Dear judges and teachers, hello everyone!I am the XX candidate of the primary school mathematics group in the interview, and the topic of my trial lecture today is "Double Understanding" to start my trial lecture below:
1. Introduce new courses.
Teacher: Students, autumn is coming, the hard-working rabbit is pulling radishes, let's take a look together, and carefully observe what mathematical information you have found in this sheet**.
Teacher: I would like to ask you to tell me, you have observed very carefully, the little rabbit has received 2 carrots, 6 carrots, and 10 white radish, so can you come up with some mathematical problems based on the mathematical information you have found?
Teacher: Tell me, you said that there are more white radishes than carrots, and how many radishes there are, and these are all problems that we have learned before, and we can solve them by adding and subtracting.
Teacher: Then let's take a look at it again, if we take the least two carrots as one serving, and how many carrots and white radishes are like this, let's count them together, circle them, and take a look.
Teacher: This is 1 2 roots, 2 2 roots, 3 2 roots, so this has 3 2 roots. So who is going to try to talk about the relationship between the number of carrots and carrots.
Teacher: Please come on, the answer is very good, you said that carrots are three parts of carrots, in fact, these three parts can be expressed by a new quantitative relationship, students want to know if they want to know, then in this lesson, let's go into the kingdom of mathematics to understand the mystery of doubling.
Two: **New knowledge.
Teacher: We have just learned that the number of carrots is as large as three carrots, and to show a simpler quantitative relationship between them, we can express that the number of carrots is three times the number of carrots.
Teacher: Let's take a look at the relationship between white radish and carrot.
Teacher: Let's count them together, circle them around, and take a look, and in the same way, we take the number of carrots as two as one serving, two carrots each, and two carrots with two sticks. 3 x 2 sticks, 4 x 2 sticks. 5 pcs. 2 roots.
Teacher: Students, think about the relationship between carrots and carrots, so how should we express the relationship between carrots and carrots?
Teacher: Whoever comes to me, please tell me, you really know how to live and learn.
Teacher: Whoever comes to me, please tell me, you really know how to learn and put it into practice, please sit down, you said that the number of roots of white radish is five times that of carrots. Students, do you all think so?
Teacher: Then if the little rabbit pulls out 2 white radishes again, how to say now, the students' reaction is really fast, yes, it is 6 2 white radish, so the white radish is 6 times that of the carrot, and then 2 more pulled, yes, it is 7 2 radish, so the white radish is 7 times that of the carrot. What about 10 2 sticks, yes, 10 times.
Teacher: Then students, let's take a look at our quantitative relationships, what are the similarities and differences between them, and what kind of conclusions can you get, first think independently, and then work in groups, the teacher believes that the power of the group is strong, and believes that your knowledge can collide with the spark of wisdom, 3 minutes, let's start.
Teacher: Teacher, I see that the students are all sitting upright, which of the students will share with you the results of your group discussion? The teacher saw that the hands of the students in group 1 were raised like a grove, so the students in the second row of group 1 said very well, please take a seat. Teacher: You said that they all had two carrots, and they were all compared with the number of carrots and two carrots, that is to say, when they were compared with carrots, these were different. Then you can get it.
When it comes to comparison, these are a few different. So what kind of conclusions can you get?
Teacher: Please tell the student in red, the summary is both concise and accurate, and the classmates give him applause, that is to say, there are several or two, and we are several times.
Teacher: Let's take a look at the big screen again, the industrious rabbit has pulled out another carrot, and now there are a few carrots, right three, so has the multiple relationship between carrots and carrots changed, and why?Bring two questions to the table and discuss with each other. Begin.
Teacher: The teacher saw that the students had finished the exchange, who would like to tell me what you think, please say, oh, now there are 2 carrots and 3 carrots, so the number of carrots is twice as many as carrots, do the students agree?
Teacher: Hey, classmates, these carrots are all 6 roots, why are there two multiples, who will say, this student with the most upright sitting posture would like you to come and say, the head is the Tao, it is really like a little teacher, please sit.
Teacher: The premise of carrots is different, because the number of carrots we have has changed, it used to be 2, so we take 2 as a portion, and there are 3 2 carrots, so it is 3 times, and now carrots.
One serving, there are 3 2 roots, so it is 3 times, and now there are 3 carrots, so we have to take 3 roots as a portion, there are a total of 2 3 roots, so it is a 2 times relationship, that is to say, when we find the quantitative relationship between two things, who is several times of whom, we have to look at who to compare with, and it is very important to figure out how much to use. Do the students understand, and then communicate and discuss with each other at the table to feel the process.
3. Consolidate and improve.
Teacher: The teacher sees that the students have finished communicating, so please take out a number of small sticks that we have prepared in advance from the school tool bag, listen to the teacher's password, put 5 small sticks in the first row, and put out 4 times the number of the first row in the second row. Teacher: There are results, who will tell me, please tell me, there are a total of 20 sticks in the second row.
Teacher: Then how do you put it, yes, because it is 4 times, so we have to put 4 and 5 sticks. A total of 20 sticks were placed.
Teacher: Then the teacher is going to increase the difficulty, let's take one small stick from the first row, then can the two rows of small sticks be used twice?
Number relationship to express it?Oh, you say 5 times.
Teacher: Who's going to tell me your reason, the reason is very good, because now the first line is 4 small sticks, and now we use 4 small sticks in the second row, there are a total of 5 4 sticks, so the root uncle in the second line is 5 times that of the first line, do you agree?It's amazing.
Teacher: Let's take a look at it again, if we add one to the first row, which is 6, can the 20 in the second row and the first row still be expressed by multiples?
Teacher: Then can you think of a way to solve this problem, please come to me, your thinking is very quick, please sit down, we can take away two roots from the second row, and there are 18 left, which is three and six roots, and the second row is three times the size of the first row.
Teacher: Is there any other way, I would like to ask you to tell us, it is also very good, we can add 4 roots to the second row, and it becomes 24 roots, that is, 4 6 roots, so the second line is 4 times that of the first row, have you thought of it?
Fourth, the class summary.
Teacher: It seems that the students have a very solid grasp of the knowledge of this lesson, and we use independent thinking and small groups in this lesson.
All the questions were done. We know, first of all, the standard of comparison, with a decimal as a part;Then, look at how many decimal places there are in the big number;Finally, a large number is a number of decimal numbers.
I believe that everyone has a certain understanding of the times through today's Xi, and after class, students can practice Xi problems after class by putting a swing and circling the math book, and we will go here in this class. After class, goodbye, classmates.
Thank you for listening. Take a bow