(1) Core content: Understand the time unit "second", initially establish the time concepts of minutes and seconds, and know that 1 minute =60 seconds can solve simple practical problems.
(I especially avoid "simply calculating time" here for two reasons: "New Curriculum Standard 2022" clearly stipulates that students should "experience the length of time in combination with their own life experience" in the first study period, and calculation and other issues are not involved in the lower stage; In Example 2 of the textbook, in addition to solving the problem by calculation, a method of calculating the grid is also provided. Besides, in ExerciseNo. 1 1, and solve the problem in two ways respectively. To sum up, students who have just entered the third grade should not ask to change their units and calculate the time across 12. Instead, I advocate using my own life experience to enrich and explore diversified time problem solving strategies. )
(2) Core literacy: Feel and understand the meaning of seconds through experience activities and exploration activities, and initially develop reasoning ability and estimation ability.
The deep learning of primary school mathematics is to cultivate the core literacy of primary school students through the learning of core content. In this unit, I think the most important thing is to cultivate the estimation ability and reasoning ability of primary school students. The foothold of estimating ability lies in understanding the time unit "second" and initially establishing the time concepts of hours, minutes and seconds. It can be embodied as "time itself is very abstract, and it is difficult for primary school students to master time." Children are in the transition stage from concrete thinking to abstract thinking. Therefore, we must create many materials that are close to the reality of students' life, design colorful experience activities, and strive to transform abstract time into concrete perceivable "quantity" so as to establish an accurate perception of time units. Here, the textbooks use 1 sec, 1 sec,1sec, 30 sec,1min, so that students can establish their own concept of time, from imprecise to more accurate estimation. Of course, this process needs to gradually form the concept of unit time in continuous estimation, verification, adjustment and improvement. )
(3) Core thoughts and feelings: cultivate a correct concept of time and form the habit of observing and cherishing time.
Second, the content analysis of the unit teaching materials of hours, minutes and seconds.
"New Curriculum Standard 2022" clearly stipulates that "combine your own life experience and experience the length of time". The goal of this course includes not only understanding the concept of time, but also establishing the concept of time. It can be seen that the teaching focus of this unit should be the understanding of time units and seconds and the establishment of the concept of minute and second time. As for choosing the right units and tools to measure the length of time, this learning task can be handled in practice class.
Throughout the entire primary school textbook system, we will find that the "time" arrangement is only four times, as follows:
The main content of the photo album unit
The first volume of senior one knows clocks. I have a preliminary understanding of the hour hand and minute hand on the clock face (note that there is no second hand), and I can recognize, read and write all the time.
When do you know the first volume of the second day of junior high school? 1 =60.
In the third grade, I knew the time unit "second" in hours, minutes and seconds, 1 minute =60 seconds, the length of experience time and the simple calculation of related time.
Year, month and day, the third day of the third book, know the year, month and day, understand the relationship between them, and understand the 24-hour timing method.
It is not difficult to find that this arrangement is a process from "big" to "small" and then to "big", that is, it follows the spiral development law of students' cognitive time from "middle to both ends" and "near to far". I think it is mainly based on the law of primary school students' life experience and abstract thinking ability.
At the same time, on the basis of students' basic completion of learning and division of these two time units, this unit has further refined the study of "second". This unit * * * consists of 7 pages, including 3 pages of exercises, which are arranged as follows:
In this unit, first, arrange to know the smaller time unit "second" and understand that 1 minute =60 seconds, so that students can grasp the relationship among hours, minutes and seconds as a whole. Secondly, experience the length of time, estimate and establish the concept of time; Finally, solve the simple problem about time in many ways.
Third, the unit open class.
According to Whitehead's theory of "three stages of romance, accuracy and integration" and the particularity of this unit, I specially arranged the unit to start classes, that is, to establish a romantic trip for the study of this unit, review and consolidate the content of "time and minutes" and make the students' knowledge system as complete as possible.
The main content of the photo album unit
The first volume of senior one knows clocks. I have a preliminary understanding of the hour hand and minute hand on the clock face (note that there is no second hand), and I can recognize, read and write all the time.
When do you know the first volume of the second day of junior high school? 1 =60.
In the third grade, I knew the time unit "second" in hours, minutes and seconds, 1 minute =60 seconds, the length of experience time and the simple calculation of related time.
Year, month and day, the third day of the third book, know the year, month and day, understand the relationship between them, and understand the 24-hour timing method.
Judging from the arrangement of teaching materials, this unit "hour, minute and second" has always been the end point of the "clock" problem. Therefore, it is very necessary to review and consolidate the knowledge of this section and let it build a knowledge block. But boring review is something that students don't like, including me. Therefore, it is planned to let students make "My Clock" by hand, which is to let them release the happiness of starting school, let them have different feelings about mathematics in the third grade, and look forward to the next study.
(1) Pre-school mobilization guidance
Students, we are students in grade three, not students in grade one or grade two. And the third day means that we have to start a different learning journey. First of all, the teacher wants to tell you a bad thing-math in grade three is very difficult ... but I believe you are all students who like to challenge the difficulty. Secondly, the study in the third grade emphasizes "learning by yourself, using words by yourself and using your brain by yourself", which is no longer what teachers always teach and talk about. For example, we must learn to preview and ask questions in the future. The teacher will take the first unit hours, minutes and seconds as examples, and I will study the methods of previewing and asking questions with my classmates.
When you go home tonight, please make a "my clock" for class tomorrow. Now, if you don't understand anything about making clocks, you can raise your hand and ask questions. (The composition of clocks and watches: hour hand, minute hand, second hand, numbers, small scale, large scale, students ask and answer; Clock making materials; The shape of the clock)
Design intention: The main purpose is to clear the obstacles that students may encounter in making "My Clock" in advance and provide some scaffolding for students. Alleviate students' fear of difficulties in making for the first time. In addition, I also reviewed and consolidated the "clock recognition" I learned in senior one.
② My work, let me introduce it.
1. Praise the students who finished My Clock and share the story of making My Clock.
2. Ask unfinished students their questions, invite completed students to help answer and guide them, and encourage them to go home from school to make "My Clock" and take it with them to study. Be sure to remind you again before school starts. )
3. Ask students to introduce my clock: hour hand, minute hand, second hand, small scale and large scale; Move the hour hand and introduce my day in minutes.
Design intent:
1: There are many reasons for the problem of homework, including students, teachers and parents. But our teachers can only control their own teachers: pay more attention to homework, praise the completion of homework, and pay attention to counseling and helping students with difficulties. ...
Of course, the most important thing is to establish certain principles and procedures, and this homework review is to provide a model for the principles and procedures of class meeting homework problems and guide students how to do it.
2. My introduction provides students with two ways of introduction, and the corresponding review is "understanding of time and minutes" and understanding of time. At the same time, to some extent, train students' language expression ability.
I have a question, let me ask it.
Are there any questions in the process of making, observing and moving the clock? At the same time, I will record the students' names and questions.
(4) I have questions and I will ask them.
Well, that's the end of our problem. Let's have a look. You asked so many questions, and the teacher asked another question: 1 How many cells are there in the grid? (Student: 5 cells) I also know that there are 5 cells! In this way, a question that knows the answer to the question can be called a "fake question".
Now, let's take a closer look at the questions we ask and think about which questions you can answer and which ones are false. ?
Please work in groups, exchange false questions with each other and give your reasons.
Group representatives find out the wrong problems.
Contrary to false questions, how to ask real questions?
(5) Summary
In today's class, we asked many questions. The great physicist Einstein once said, "It is often more important to ask a question than to solve it." I hope that students will ask more questions, be good at asking questions and be good at asking questions in future study. In addition, there are many real questions waiting for us to answer on the blackboard. Starting from the next class, we will formally enter the "every minute" study.
Fourth, think after class.
This is an old unit class, which is designed for my students in Grade Two, Book Two. Because I am familiar with it, the design is a little deeper, but because the job transfer has not been implemented. Fortunately, I have also taught junior three students after transfer, which is somewhat useful. First of all, I had a "pre-test of learning challenge sheet" in my class on Monday afternoon. The knowledge that students have learned before is very solid, but I don't know why. In the course of the pre-test, we also found that students are particularly cute-sitting posture, small gestures, and random answers ... While restraining this cuteness, we also compiled and produced My Clock one by one.
This morning, I arrived at school very early and immediately went to class to browse. This is really a bit disappointing. If it were those old children, they would certainly surround me at the door and show off their clocks. It doesn't matter. I'm sure these children will, too Since no one is showing off, I'll ask. When I first asked, two students took it out. Although I know how difficult it is to do, I still can't accept it. Fortunately, after I carefully watched and praised them, more than a dozen students showed their courage. ...
The first lesson mainly introduces my own clock and my clock, and draws out several students to introduce the short story "My clock". Knowledge is mainly to review and consolidate the "minutes, hours and scales" learned before. The second class is a new class, and the main content to be solved is "What is a second? Why 1 =60 seconds? " The first question was completed step by step, and the effect was not bad. The second question is mainly demonstrated by courseware, "The second hand walks a big circle and a small square in minutes". In the episode "1 min", students are not clear about the concept of 1 min, which leads to the equation never fully understood. Fortunately, I found this loophole and fine-tuned the definition in the book. This also tells me that we must attach importance to students' original concept, that is, learning situation. This statement seems to be not specific enough, so it may be more convenient to express it: list all the knowledge that students need to learn this knowledge point, and then classify it as "learned" and "not learned" It should be noted that the unknown must be about to learn, and it also accounts for 20% (the highest) of the total knowledge. This means narrowing the scope and learning in the most concise and efficient way.
So what is learning love? I think it is the knowledge that students have learned (only this piece of knowledge), the common sense that all mathematicians know, "Mathematics is logical and emphasizes the foundation." If you don't master math well in the early stage. There will be obstacles in the subsequent math study. In the logical chain of mathematics, if one link goes wrong, it may affect the rest. It is particularly important to learn every step of mathematics well. "
"Playing Games to Learn Mathematics" particularly emphasizes the need for pre-test study guidance, the main reason is to clarify these four issues! This is also the focus of knowledge: 1. What is the development level of existing ideas in children's minds? 2. What are the characteristics of the existing ideas in children's minds in daily life? 3. What new problems may the existing ideas in children's minds have cognitive conflicts with? (Pay attention to the degree of grasp)