The problems in the second grade of primary school make some parents scratch their heads. The key is not that they can't solve the problem, but how to teach children how to think in their existing knowledge field and really let them understand.
Topic: Class 1 has 20 students, Class 2 14 students. How to adjust the number of students to make the two classes equal?
Analysis: To make the number of students in the two classes the same, we can't use the equation of the second-grade children's knowledge field, but only explain it to the children by moving objects. There are three ways to solve this problem, namely, removal, addition and division.
First, remove more. Compared with Class Two, Class One has more people, not including Class One. Business trip first: there are 20- 14=6 people in class one than in class two, and then these 6 people should be equally assigned to two classes, that is, 3 people in each class, and finally it is concluded that 3 people will be eliminated in class one.
Second, add less. Similarly, if there are fewer people in Class One than Class Two, then give more people to Class Two with fewer people. First of all, the business trip: Class 2 is 20-1 4 = 6 people less than Class 2, and then these 6 people should be evenly distributed to two classes, that is, 3 people in each class, and finally it is concluded that Class 2 plus 3 people.
Third, separate redundant people. The same idea, first make differences, and then divide the number of people. Give it to each class after separation.
Topic: Ask this question in turn and think about it. There are 34 people in class one and class two, and there are as many people in class two after three people are transferred from class one. How many people are there in Class One and Class Two respectively?
Option 1: Step 1: Think about how many people are in 34 classes. 34 can be divided into 30+4, and each class is divided into 17 people; The second step is to think that there are as many students in two classes after one class is transferred to three classes. The meaning behind this sentence is that there are many students in class one, that is, the number of students in class one is 17+3=20 and the number of students in class two is 17-3= 14.
Option 2: First, look at the number of people in two classes after transferring three people from one class to two classes. This sentence means that class one is more than class two. How many people are there? According to the above questions, it can be concluded that there are two more 3s, that is, six people, and Class One has six more people than Class Two.
Step two, think about it. How many people are there in Class One and Class Two, not counting the six extra people? 34-6=28 people, and these 28 people are equally assigned to each class, that is, each class 14 people; Step three, think about who the six extra people are. One class is more than two classes, that is to say, there is more than one class, 14+6=20 students, while the two classes are 14 students.
Exercise: There are 88 students in Class One and Class Two, Grade Two. If you transfer four students from Class One to Class Two, the number of students in Class Two is the same. How many people are there in Class One and Class Two, Grade Two?
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