"Decomposition and Composition of 8" 1 I. Activity Objectives
1, through hands-on operation, guide children to perceive the decomposition of 8 and master the seven points of 8.
2. On the basis of the decomposition and composition of perceived numbers, master the laws of number increase and decrease and mutual exchange.
3. Develop children's observation and analysis ability and cultivate children's interest in mathematics.
Second, the focus and difficulty of teaching
Key points: perceive the relationship between the whole and the part, learn and record the seven points of 8.
Difficulties: Summarize the law of decomposition and synthesis of numbers within 8.
Third, activity preparation
Combine the numbers within 1 and 8 into a teaching video.
2. Some pictures of dwarfs and small houses.
3. Some digital cards.
Fourth, the activity process
(1) Review the composition and decomposition of numbers learned before in the form of questions and answers. For example:
Teacher: Little friend, we have learned the decomposition composition of 7 before. Shall we review it? I'll ask, you answer, how much can 7 be divided by 3 and? Child: You ask me and I answer. Seven can be divided into three and four. (Children clap their hands to answer)
(2) Learn the composition and decomposition of 8.
1, story import. Teacher: In a dense forest, there lived a beautiful Snow White. Today, Snow White is very happy, because a small guest has come to visit the forest. Look, here they come.
Ask questions:
How many dwarfs have been here < 1 >?
< 2 > Eight dwarfs want to live in two small houses. How should they live? The topic "Decomposition and Synthesis of 8" is introduced.
2. Children begin to operate, put eight dwarf cards on the table, and remember all the points they think about 8 to help Snow White make different arrangements.
<1> Divide the children into two groups with three people in each group.
< 2 > Please ask one child in each group to take notes, and the other children to do the operation.
< 3 > The teacher summed up 7: 08 according to the child's operation:
8 8 8 8
∧ ∧ ∧ ∧
1 7 2 6 3 5 4
7 1 6 2 5 3 4
3. Guide children to observe the decomposition formula of 8, and find out the decomposition law of a number within 8: divide a number into two parts. If one part increases 1 and the other part decreases 1, that is, the law of increase and decrease.
eight
∧
1 7
2 6
3 5
4 4
5 3
6 2
7 1
(3), consolidate the exercise
1, fill in the card number.
8 8 8
∧ ∧ ∧ ………
5()7()5()
3.8 decomposition and synthesis of teaching video.
(4) Activity extension
1, the train has left. Rules of the game: Every child has a digital card, and the children whose numbers add up to 8 get on the bus hand in hand and walk out of the activity room while singing the song "The train is leaving".
Reflection on the Teaching of verb (abbreviation of verb)
In this class, I started from the children's existing knowledge, combined with the children's actual life and age characteristics, and created a vivid and interesting story situation, so that children can try to explore, learn and master the method of dividing 7 by 8 by themselves through vivid and interesting activities such as posing, recording and talking. On this basis, children can express the process of division and combination in clearer language, and also discover and summarize the law of decomposition and combination of numbers within 8. During the activity, the children showed great interest and experienced the joy of success. The disadvantage is that in the last game session, the children forgot to find their "good friends" in a hurry; Individual children have poor hands-on ability and participation consciousness, are unwilling to communicate with their peers, and need to strengthen training.
The Activity Target of Chapter 2 "Decomposition and Composition of 8" in Mathematics Teaching Plan for Large Classes
Learn the composition and decomposition of 8 and master 7 combinations of 8.
Understand the addition and subtraction of 8.
Activities to be prepared
Experience preparation: children have mastered the division and combination of 2-7.
Courseware preparation: "Go to the playground" scene picture; "8 on and 8 off" group map; Pictures of "The playground is really happy".
Activity process
Show the picture of the scene "going to the playground" and guide the children to try the division and combination of 8 with their existing experience.
Panda Kiki and Miaomiao went to the playground today. The conductor said that children must pass mental retardation to enter the playground.
-originally wanted to say the splitting formula of 8. Can you try it?
Summary: 8 There are 7 kinds of separation and combination.
Show the group diagram of "8 on and off" to guide children to understand the addition and subtraction formula of 8.
-8 can be divided into 1 and 7, so 1 and 7 add up to 8, and we can get the formula 1+7=8. According to the formula exchange law, we can derive another formula 7+ 1=8. According to the division and addition formula of 8, the formula 8- 1 = 7 can be obtained, and according to the exchange law of the formula, another formula 8-7 = 1 can be deduced. (and so on to complete all the addition and subtraction formulas of 8)
Show pictures of the scene "The playground is really happy" and encourage children to write formulas according to the picture tips.
-We helped Qiqi into the playground. They had a good time. Let's see what the props arrangement in the playground means!
-How to write these props into formulas?
Organize clapping games to guide children to further consolidate the decomposition and composition within 8.
1, the teacher explained the rules of the game.
The teacher said a number first, and then clapped his hands. When the teacher finishes your clapping, you clap your hands as many times as the teacher.
These figures add up to what the teacher said. For example, if the teacher says five, you clap your hands three times and you clap your hands twice.
2. The teacher says the number "2-8" and leads the children to play games.
The Activity Intention of Chapter 3 "Decomposition and Combination of Eight" in Mathematics Teaching Plan for Large Classes;
Mathematics teaching activities must be based on children's cognitive development level and existing knowledge and experience, and interest is the best teacher. Combined with children's personality characteristics, the activity of "synthesis and decomposition of eight" was carried out, which stimulated children's thinking and their interest in learning mathematics.
Activity objectives:
1, consolidate the decomposition and composition of 8, and lay the foundation for calculation.
2. Cultivate children's ability of analysis, judgment and reasoning.
3. Cultivate children's ability to observe, judge and operate.
4. Guide children to actively interact with materials and experience the fun of mathematics activities.
5. Develop children's logical thinking ability.
Activity preparation:
Demonstration board, digital operation box (snowflake), white paper and pencil.
Activity flow:
First, children listen to music and take smart boxes in order.
Second, the composition of memory 8
1, touch the ball game, touch the number 8.
1 How many balls did you touch?
1 The ball touches 7 balls.
How many balls do three balls touch?
Three balls touch five balls. ...
2. Composition of Game Comment 8.
III. Decomposition and Combinatorial Learning 8
1, display the digital display board, and put two colors in the squares of the display board.
2. Read them according to different points.
3. Write the corresponding formula on the blackboard, and so on.
There are 8 rabbits in the park. The elephant asked three rabbits to go. How many rabbits are left?
5. What does this question tell us first? Tell us what later? What kind of people do you want us to be? How to divide by decomposition? 8 can be divided into 3 and 5. Please list individual children: 8, 3, 5, etc.
6. Observe the schematic diagram of the decomposition and composition of 8, and understand the increase, decrease, supplement and exchange relationship between the whole and the parts.
Fourth, children operate to enhance the experience.
Children begin to operate, and teachers tour to guide them. Try to record their operation results on white paper and list the correct formulas.
Activity reflection:
Children are the masters of mathematics learning, and teachers are the organizers, guides and collaborators of mathematics learning. In the classroom, the child is the protagonist and the teacher is only a supporting role, leaving time and space for children to think, explore and communicate, and paying attention to their emotions, attitudes and thinking in the learning process. Intersperse games or organize some interesting activities in the activities to improve children in a pleasant atmosphere.