First, it is said that the textbook "Think about it" is a pure mathematical exploration and practice activity class. This teaching content is a practical activity arranged after learning 100. Students can further understand the composition of numbers within 100 and the concepts of numbers and bit values by swinging a chess piece. First-year students are unfamiliar with numbers within 100, and the most basic knowledge is the order of numbers; To be clear, the same number on different digits means different numbers; It is also necessary to understand the composition of a number, which can be divided into two numbers (or the sum of two numbers) not greater than 9. In view of the young age of the students, the above content is difficult to understand. This practical activity makes full use of children's psychology that they like to play with hands, guides them to learn interesting habits, and designs vivid and interesting "playing methods", so that children can feel the numbers within 100 in hands-on operation, understand and understand the relevant basic knowledge, and get a good feeling. This lesson is to make abstract and boring numbers let students "play" with mathematical truth. The textbook shows two examples of activities. Students can imitate the activities in the textbook. First, the elf asked a question: "Can two ● be used to represent different numbers?" (At present, the number students learn is limited to 100, and the number here only refers to one digit and two digits. ) The following is a group of four students. Three of them put CDs on a digital table and say the numbers according to the number of CDs of ten and one. For example, two CDs are placed in one place, which means that the number in one place is 2, and this number is 2; Both disks are placed in the tenth place, indicating that the number of the tenth place is 2, the unit number is 0, and this number is 20; Put a disk for each number and unit, indicating that both numbers are 1, and this number is 1 1. Another student synthesizes these three answers through a list. On the left of the list is the number of discs used, and on the right is the number of three. Here, students are required to understand the concept of bit values of different digits (2 in ten digits means two tens, and 2 in one digit means two ones), and at the same time master the composition of 2 (sum is the addition of 2): 2=0+2, 2= 1+ 1, 2=2+0, so that they can be presented without repetition or omission. Next, in the same way, three students who are in charge of posing put out three numbers: 3, 12, 2 1. The students who are in charge of the list have written all the answers on the paper, but they think there are still numbers that have not been put out, prompting the students to think about what numbers can be put out with three besides the above three numbers. Next, the elf asked a question "4 ● and 5 ● ...? "Prompt the students to put a pendulum in the same way and complete the other situations in the list. Finally, the textbook requires students to say what number 9 can represent ● Don't pose. This requires students to find out the law in the process of pendulum and get the answer by induction. According to the requirements of the new curriculum standards, the characteristics of students and the characteristics of teaching materials, I set the teaching objectives of this course from three aspects: (1) Through this practical activity, let students experience the fun of learning mathematics, stimulate their emotions and desires to explore knowledge, cultivate their sense of cooperation and competition, and establish their self-confidence in learning. (2) Through exploration activities, cultivate students' cooperative consciousness and observation ability, image thinking ability and language expression ability, as well as preliminary inductive and abstract thinking ability. (3) Through this activity, students can consolidate their understanding of the number within 100, and learn to summarize and sort it out in the process of active exploration. Second, teaching methods, learning methods Because this class is a math activity class, it mainly focuses on student activities. This class mainly takes the form of group cooperation activities. Students explore independently, cooperate and communicate, and the teacher only plays a guiding role. Third, the teaching process According to the above teaching objectives, I made the following design for this class. 1. Review. Because this activity requires students to be familiar with the concepts of numbers and bit values, before starting the activity, I use a number table and a counter to review relevant knowledge. For example, the ten digits and one digit of a counter are two beads. Let's talk about what the two beads represent first. 2. Stimulate interest and explore knowledge. Ask questions with Cong Cong and Ming Ming, two lovely elves familiar to students, and introduce new lessons. For example, the elves from these two math kingdoms also come to our activities to stimulate students' interest in learning. In the process of exploring knowledge, we should give full play to the cooperation of four people, pay attention to all students, let all the senses participate in learning, and let students acquire knowledge and experience the happiness of success through independent exploration and cooperation. 3. Combine guidance with release to cultivate students' ability. In this activity, I pay attention to leave as much space and time as possible for students to observe, think, discover laws and summarize. Strive to achieve: teachers will never replace any problems that students can solve; Let the students do it, let the students say it. Students acquire knowledge through hands-on practice, independent exploration and cooperative exchange, thus cultivating students' various abilities. In short, the design of this course is guided by the educational concept of "student-oriented development", and strives to follow the principle of "teacher-oriented, student-oriented", so that students can actively participate in the whole teaching process, learn easily, give full play to the main role and discover their own intelligence. Teacher: Are you happy that so many teachers have come to class today? Then the teacher depends on which child in our class is the best, the smartest, the most fond of thinking, and can get the wisdom flowers sent by the teacher. Review the bedclothes 1. Numeric order. 2. Teacher: First, the teacher asked a question. We have learned the understanding of numbers within 100. Who can tell you which side of the numerical order is the first and second? What about the third place? Teacher: What do the numbers in the unit mean? What does the tenth digit mean? What about the numbers in hundreds? 2. Dial the number with the counter. Teacher: Now the teacher dials a number on the counter. Look carefully. Ten people each pluck two beads. What's this number? Who can tell what 2 in these two digits stands for? (the student answers. What you said is really good. Everyone applauded him. Teacher: Now, please take out your counters. When I say count your balls, be careful when dialing 4, 13, 22, 3 1 40. Health: 4, dial 4. 13, ten digits dial 1, and one digit dial 3. 22, dial 2 for ten digits and 2 for one digit. Teacher: What did you find when the children dialed these numbers just now? The figures on the table add up to 4. Compared with the previous adjacent numbers, each number has one less digit, ten more digits and a difference of nine digits. ) teacher: what you said is really good! After listening to your speech, the teacher was very happy and everyone applauded him. Next, please put the counter in the corner of the table, take out the electronic watch and the prepared disc, and let's have an interesting activity. This activity is called "posing thinking" (asking questions). In this activity, everyone should be good at using their brains and looking for rules to make our activities go on quickly and well. Stimulate interest and cooperate with knowledge teacher: Look! Who is our good friend? (Congcong and Mingming. ) The elves from the two math kingdoms also came to our activities. Show me the problem. ) Look, Cong Cong asked us a question, "Can you use two disks to represent different numbers? "1. Count with 2 discs. Teacher: Can everyone? One thing to remind, so far, the number we have learned is limited to 100. Therefore, only one digit and two digits can be put on the digital table, not three digits. Let's start with two disks and see what numbers can be put in. Teacher: Who will tell you how you set it up, classmate? To be clear, where did you put the wafer? What's this number? Pre-production 1: I put two CDs in one place, which is 2. Health 2: I put both discs in the tenth position, but neither position is 20. Health 3: I put 1 wafer in the tenth place and put 1 in the unit, which is 1 1. Blackboard: 2 discs. 2, 1 1,20。 Teacher: Let's think about it. Why do two discs in one place get 2? Put it in the tenth place, the number is 20? Health 4: It's 2 because it represents two ones in one place, and it's 20 because it represents ten places and two tens. Teacher: You speak very well! Everyone applauded him. Next, I'll tell you, look! Another good friend of ours, the elf, also joined in the fun. Who is he? (Mingming) Yes, the elf obviously wants to ask you questions (show questions). (1) Can three disks represent different numbers? Can everyone answer him? (2) Use three discs to set the quantity. Please set it manually and see how many numbers can be set. Tell me what you said. Blackboard: 3 discs, 312,2130. Teacher: What did you find from these two sets of figures just now? How do I know the number is not lost? Good answer (applause). You are so clever. 2. Count with 4 discs and 5 discs. Teacher: Look, these two little guys asked us a difficult question: "What different numbers do the four disks and the five disks represent? "... all right! Everyone is so brave! You are not afraid of difficulties, and your spirit of exploration makes the teacher admire you. 3. Teamwork, * * * and exploration. Teacher: Next, we will cooperate in four groups and discuss with each other what numbers can be put on several discs. Teachers in each group send out a summary table and then work together. Three students put the CD on the digital desk, and the group leader took notes on the summary table. On the left side of the table is the number of discs, and on the right is the number of discs released. Teacher: Note: Students who take notes should sum up the figures put by three students in your group. Do not have duplicate numbers. Let's see which group writes fast and well, and the students write big and neatly, and the activities begin. (The teacher patrols. ) teacher: be good at thinking and discovering rules when playing, so it is fast and not easy to miss. 4. Student report. Teacher: What numbers can be put on four disks, and which group will report to you? Health: We set five numbers with four disks (blackboard: four disks, 4, 13, 22, 3 1 40). Teacher: Tell me about your experience. How do you speak so fast? (praise this group. ) teacher: how many can I put in five disks? (Blackboard: 5 discs, 5, 14, 23, 32, 4 1 50) Which group should be supplemented? 5. Dare to imagine and explore the law. Teacher: Did you find any rules from the process of children counting with a disk just now? Let's not put the CD below. Can you think of a way to put the disks in your head and write directly what numbers six disks, seven disks, eight disks and nine disks can represent? Ok, four people work together to see which group fills in quickly and well! Student report, teacher writing on the blackboard (omitted). In short, students should be encouraged to use their brains and come up with as many methods as possible to form communication. Teacher: Are all the groups over? Please come to the front and show your group's work to everyone. Do you comment on each other? Teacher: Has everyone finished eating? Look at the blackboard together. Judging from the number of discs we played and the number written on them, did the students follow any rules? Who can say something? Summary: Who can tell us what we learned today? What have you gained? I hope everyone can learn to observe, be good at using their brains and find out the rules in future study, so that our study can improve efficiency.