The second stage: pre-operation stage (2-7 years old), children are self-centered, that is, they will not think from the perspective of others. In order to prove this point, Piaget made a famous three-mountain experiment. He asked the children at this stage to observe the shapes and sizes of the three mountains from four directions and take corresponding pictures, and then asked the children to choose the pictures consistent with the shapes and sizes of the mountains that the puppet sitting opposite him saw. As a result, the child at this time chose a picture that matched the shape and size of the mountain from his own point of view. To sum up, children at this time are self-centered; Second, I firmly believe that everything has a spiritual wheel. At this stage, children think that everything is alive, so you often see children talking to their puppets at this time. They prefer their parents to tell him fairy tales. Third, the rigid thinking is mainly manifested in two aspects: on the one hand, the thinking is not conservative. Piaget did a measuring cylinder experiment. He poured the water from the coarse measuring cylinder into the fine measuring cylinder and asked the children at this stage which measuring cylinder had more water? The children replied that there is a lot of water in the measuring cylinder, because the water level in the measuring cylinder has risen, which shows that the children at this stage can only consider the problem from one dimension and can't figure out the relationship between quantity and quantity, so it is not conserved; On the other hand, this kind of thinking is irreversible. In other words, children at this stage only know that Xiao Ming's brother is Xiao Gang, but they don't know that Xiao Gang's brother is Xiao Ming, that is, they can't figure out the logical relationship between things.
The third stage: the specific operation stage (7- 1 1). At this stage, the characteristics of children are just the opposite of the previous budget stage. It is recommended that students remember by comparison when reviewing. At this stage, children first show themselves as self-centered and begin to learn to consider problems from the perspective of others; Secondly, this kind of thinking is conservative, that is, children at this stage will tell you how many apples there are after this apple is cut into four pieces, and this kind of thinking is reversible. Children at this stage not only know that Xiao Ming's brother is Xiao Gang, but also know that Xiao Gang's brother is Xiao Ming. But the thinking at this time must rely on the support of concrete things, so teachers should adhere to the principle of intuition in teaching;
The fourth stage: formal operation stage (1 1- 16), with abstract logical thinking ability, and can solve problems by inductive and deductive methods; Second, children at this stage can understand the meaning of symbols, which has certain generality, such as understanding the meaning of "life" and "death"; Third, children's thinking at this stage is not only reversible, compensatory, but also flexible. For example, there is a balance with 5g items on the left and 10g items on the right. Ask the children at this stage how to keep balance. His answer may be to move the fulcrum between scales according to the lever principle to maintain balance.
To sum up, Piaget's theory of cognitive development stages gives us two inspirations: first, the cognitive development stage will restrict the teaching content and methods; Second, teaching will promote students' cognitive development.