People are dynamic individuals, and learning is the process of learners' active construction. The development of society also strongly needs to develop children's initiative and creativity. Mathematics is an abstract logic subject with its own characteristics and laws. It is closely related to children's life, and mathematics activities should be designed in combination with children's life reality and knowledge and experience. In the mathematical activities of "two-level classification", I hope to provide children with sufficient operating materials, and then guide them step by step, so that children can truly discover and summarize the characteristics of "two-level classification of graphics" in the process of operation. Because the formation of children's mathematical concepts can not be solved by listening to the teacher and watching the teacher demonstrate, it must be through the process of children's own active activities.

Second, the analysis of children's situation

The cognitive, operational and logical thinking abilities of children in large classes have been continuously improved; At the same time, they are not only satisfied with what the teacher said, but also often ask questions such as "what is this", "why" and "how to do it". They are more willing to prove it through their own abilities. Therefore, they are more interested in operation. At present, children in large classes can basically classify graphics and things independently, but they can't classify things graphics twice. Moreover, because children are not mature in all aspects of development, they may understand something, but they can't transform it from concrete to their own internal abstract concepts. Therefore, through activities, I hope they can turn their understanding of the external characteristics of things into internal and regular thinking.

Third, say the goal.

The new syllabus points out that the value orientation of science education is no longer concerned with the transmission of static knowledge, but with children's emotional attitude and children's ability to explore and solve problems. Children are active participants rather than passive recipients of educational activities, and the content of activities must meet children's interests, needs and acceptance, so as to guide children to develop to the nearest target development area. Children in large classes like to explore and try, and are very interested in moving and doing, so I inspire them to communicate and discuss after operation, accumulate experience, and guide them to discover the regular characteristics of "secondary classification of graphics". Therefore, according to the goals in the mathematics field in the syllabus and the actual situation of children, I will position the goals of this activity as follows:

1, through activities, let children feel the relationship between things from life and games, and experience the fun of discovery.

2. Cultivate children's logical thinking ability to discover, observe, compare and summarize the characteristics of things through their operation and exploration;

3. Guide children to say the characteristics of two-level graphics, experience the inclusion relationship, and learn the two-level classification.

These three goals include the cultivation of mathematical ability, the acquisition of active exploration experience and the improvement of the ability to summarize things, and the comprehensiveness and hierarchy of the experience goal. I put the focus of this activity on "cultivating children's ability to discover things, observe things, compare things and summarize things", so I threw out this question at the beginning, "How to separate so many mixed graphics? What method do you think can be used? " From the gradual deepening of the first and second links to the final classification according to the two external characteristics of the object, the focus will be slowly digested and absorbed; Then, how to internalize the experience into your own knowledge and experience; Then, the difficulty is "how to make children understand the inclusion relationship". I decided to break through the following points:

1, children should find ways to classify themselves first; Specific operation;

2. Teachers demonstrate and guide to help children understand the basic features of secondary classification: after classifying according to one feature, classify the two types of graphics again according to another feature. Here, I will demonstrate with building blocks. First, I will mix two different triangular, cylindrical and rectangular building blocks, red and yellow, and then I will ask the children to help me divide them into two groups (then, there are only two colors, but there are three figures, so the children will divide them into two groups by color first). Then, I will let the children divide into groups (naturally, the children will use graphics to classify).

3, the child will operate again.

4, experience transfer: for example, let children do secondary classification.

"Please classify children twice" (generally, children are divided into men and women first, and then classified on the second floor according to height, clothes, hair, etc. )

Fourth, activity preparation

1, red, yellow and blue square, circle and triangle; 2, all kinds of building blocks

Teaching methods of verbs (abbreviation of verb)

In order to achieve the purpose of this activity, I adopted the following methods: trying operation, language discussion and game.

1, try operation method: In mathematics teaching, it must be emphasized that children should operate materials by themselves, explore and learn in actual operation, and gain perceptual experience about mathematical concepts. Only in the process of "doing" and interacting with materials can children experience a certain mathematical concept attribute or law and gain direct experience. In this activity, I gave the children a lot of operating materials: all kinds of red, yellow and blue squares, circles and triangles, so that the children could try to find a classification method and sum up their experience after playing by themselves.

2. Language discussion: In mathematics education, discussion is a commonly used method, but it will have different effects on children's specific operation and thinking activities at different operation times. Therefore, at the beginning of the activity, I will first guide the children to discuss the classification method, and then let them discuss "what method do you use" after the operation. In this way, through constant communication and discussion, with the help of teachers, children will form the concept of secondary classification in their own minds.

3. Game method: Through the game of "See who can lift fast", let children further achieve the purpose of playing middle school through competitive games, develop children's thinking in the game, and turn passive into active, which not only consolidates and deepens knowledge, but also improves the ability of analysis, comparison and generalization.

At the same time, in the process of children's learning, teachers should face the whole and pay attention to individual differences, so that each child can improve to varying degrees. According to the difference of children's ability, I guide the children with strong ability to observe first, and then try to find the best classification method. After trying one by one, children with weak guiding ability get the characteristics of secondary classification.

Sixth, the teaching process:

According to the age characteristics of children in large classes and the target requirements of this activity, I designed the following links:

1, stimulate children's enthusiasm for activities through games;

2. Enlighten and induce, master knowledge and develop ability in free operation: first guide children to observe different points (colors, shapes and sizes) of graphics, then encourage children to operate freely, gradually deepen in free exploration and find classification methods;

3. Explain the experience and exchange different methods: pay attention to the exchange and sharing of experiences between children, encourage children to share their findings according to their own operation results, and experience the joy of discovery. Then every operation link has a summary from teachers and children, focusing on the consolidation and induction of experience.

4. Children undergo reoperation;

5, game activities, expand ideas and deepen the impression.

Activity flow:

1. Learn to classify objects according to their two external characteristics. (This link is mainly to stimulate children's enthusiasm for activities. )

(1) Game: "Let's see who can lift fast" The teacher gives instructions, such as: Please lift the X-shaped XX; Or please hold up the big X. After hearing the signal, the child should quickly lift the figure according to these two characteristics to see who can lift it quickly.

2. Learn to classify graphics twice.

(1) Show some red and blue circles, squares and triangles. Ask the children to come up and divide the geometric figures into two categories according to their colors, and then ask two children to come up and divide the red and blue figures into three categories according to their shapes (i.e. red circles, squares, triangles and blue circles, squares and triangles), and initially learn how to divide the figures into two categories.

(2) Distribute operation materials to children for operation. Everyone has a set of squares, circles and triangles of different sizes. First, separate the large and small graphics, and then divide the large graphics into three categories according to circle, square and triangle. Then the small graphics are divided into three categories according to square, circle and triangle, which require orderly operation.

(3) The teacher concluded that children should operate again and make secondary classification.

3. Experience transfer:

For example, ask children to make a second classification. "Please classify the children twice."

4. Activity summary: Teachers analyze and solve the problems in children's classification activities to help children gain classification experience.