First, the number of cognition In the comparison of children's learning sets, children generally use three basic ways to compare the size of sets in mathematics learning, namely visual clues, one-to-one correspondence and counting. These three methods have their own advantages and disadvantages. Among them, the advantage of visual prompt is that it is convenient and simple to operate, but it is easy to make mistakes; One-to-one correspondence has the advantages of intuition and accuracy, but it is used less frequently; Counting method is the most accurate and practical of the three methods, which can accurately reflect the present situation of children's mastery of set comparison and has an important basic role for children to learn large set comparison in the future. But relatively speaking, its operation is more complicated. Persistence in the game, the division of labor and negotiation ability of game roles, and cooperation ability are all honed. (D) The combination of various evaluation methods can improve the evaluation efficiency. In the previous game evaluation, most children were "talking in general terms" and only talked about their respective topics of concern. For some "key problems", teachers often tell the solutions directly. It can be said that evaluation efficiency is not an "evaluation room", which allows teachers and children to quickly focus on a certain field for key discussions and avoid messy and scattered discussions. Moreover, it is not implemented in isolation, but complementary and flexible with other evaluation forms, such as centralized evaluation after the game and oral random evaluation, which makes us realize that the combination of various evaluation methods can improve evaluation efficiency, give children more autonomy and leave them more time and space to pay attention to themselves and others. From this. Evaluation can better promote the development of children and games. Remarks: [1] Bi Xiaofen. Effective strategies for role-playing evaluation in large classes [J]. Education Guide (second half), 20 1 1 (10). (2) Qian Jingying. Improve children's game level with diversified game evaluation [J]. Education Guide (2) wanfang data (1) Visual cue is a method to estimate the number of objects in a set according to observation. Piaget's research on the conservation of quantity points out that "children always like to judge the quantity according to the visual clues when solving the problem of conservation of quantity." (2) In other words, children often use visual cues such as length, area or arrangement density to compare the size of a collection, because it is more convenient and simple. However, the information of the number of sets obtained in this way is general, and this way is easily influenced by many factors such as the arrangement formula of objects and the number of objects in the set itself, which leads to the deviation of children's conclusion on the final set size. (2) One-to-one correspondence means that in two sets, each element of one set forms a corresponding relationship with each element of the other set. (3) One-to-one correspondence can intuitively present the quantitative relationship between sets, and the conclusion of "who has more and who has less" is also accurate. However, this method is limited by the size of the set, and it is not easy to present a one-to-one correspondence when the set is very large. At the same time, if there is no obvious auxiliary means (connection, etc. ), children will not take the initiative to use the one-to-one correspondence method to compare the sizes of the two groups-how many times can children compare the objects that have been placed in two rows with one-to-one correspondence, but they will not take the initiative to correspond to another row of objects based on one row of objects. [4J (3) Counting is another accurate method to compare the sizes of sets. By counting, children can know the number of sets more accurately and compare the sizes of sets. Moreover, in the comparison of sets, counting is more widely used than one-to-one correspondence, because counting not only emphasizes "who has more and who has less", but also emphasizes drawing conclusions through the comparison of numbers in sets, which is conducive to the consolidation of children's logarithmic learning and has a basic role for children to participate in more advanced addition and subtraction operations in the future. However, counting also has certain limitations, which requires children to master the skills of counting skillfully. Generally speaking, counting is an accurate and practical method, which is of great significance for children to master the comparison of sets in depth and is an effective method for children to compare sets. Then, why is counting different from other ways and becoming an effective strategy for children's collection comparison? What are the developmental characteristics of children's comparative set and counting? 37 Features 00000 Second, grasp the collection comparison of children by counting (1) Understand the collection comparison process of children by counting. Compared with visual cues and one-to-one correspondence, it is more complicated to compare sets by counting. It includes not only the counting process, but also the comparison process of memory and numbers (take Figure L as an example). Teachers should realize that children can only do it on the basis of the above three aspects. Only in this way can we realize the process of set comparison with numbers. Figure 1 shows the process of comparing sets by calculating subitems. Determine the number of groups. The first step in comparing sets by counting is to determine the number of sets. As shown in the above example, children determine the total number of five-pointed stars in the left and right groups by counting. Correct counting is the basic condition of set comparison. Germans and Galileo put forward five principles of correct counting: one-to-one correspondence principle, fixed order principle, cardinal number principle, abstract principle and order independence principle. Simply put, counting is to enable children to accurately say the order of numbers and understand that the number of the last object in the counted set represents the total number of sets (as shown in the above figure, the set "8" on the left represents the total number of this set). 2. The number of memory sets. Just like the above example, after determining the numbers of the eighth and ninth groups, children should be able to remember these two numbers. What needs to be explained here is that counting and remembering numbers may happen at the same time, and there is no order. In other words, after counting to 8, you should be able to remember 8 and count the next set at the same time. If the child can only remember the total number of the next set. Then the result of set comparison will be wrong. Therefore, before comparing these two figures, children should be able to remember the total Wan Fang data of the two groups in a short time. As in the above example, on the basis of obtaining the total number of the left and right groups, children should compare the sizes of 8 and 9 to determine whether there are more five-pointed stars in the left group or more five-pointed stars in the right group. In the comparison of two numbers, a very important basis is the logarithmic hand grasp method, that is, children can determine who is in front and who is behind the two numbers 8 and 9 in numerical order. The so-called number order, that is, the order of natural numbers, the arrangement of each number in the probability sequence is arranged in the order that the last natural number is more than the previous natural number by "L".