Which student hasn't played the slide! This is the students' existing life experience, and finding the angle from the slides and matching the measurement of the angle with such a life prototype requires teachers to have the wisdom to create a suitable situation.
Second, create an activity situation and highlight the experience.
For those mathematical knowledge that cannot be clearly presented and fully explored by relying on teachers' demonstration and students' imagination, teachers can create activity situations and lead students to gradually accumulate intuitive representations of abstract knowledge in practical activities that they have experienced personally. For example, when teaching "Left and Right", teachers may wish to organize students to carry out various lively and interesting activities and experience the relativity of left and right.
The first activity: Through the activities of the left hand and the right hand, we can feel our left and right. Let the students raise their hands and talk about what their right and left hands can do, so that they can feel their right and left hands. Then let the students find the left and right sides of their bodies and experience them. Finally, let the students get familiar with the left and right by playing small games and listening to instructions.
The second activity: play with school tools and get to know the left and right. First of all, let the students put the school tools in order and know the left and right. Then count them in left and right order, so that students can understand the same learning tools. If you count from different directions, the order is different and the results are different. Finally, talk about the relationship between learning tools and left and right positions.
The third activity: let students participate in the whole process of knowledge formation and experience the relativity of left and right. The teacher raised his right hand in front of the students and asked them to judge whether it was right or not. Through argument, the teacher raised his right hand and turned around to confirm the conclusion. "The teacher raised his left hand with us. Why do they all raise their left hands, but they look different? When students think about this problem, they will find that the left (right) hand will be just the opposite because of the opposite direction.
Third, the creation of questioning situations, highlighting the exploration
Guiding questions is an important prerequisite to stimulate students' subjective thinking and learning behavior. Students' problems are the growing point of mathematical knowledge. Teachers skillfully present some interesting materials closely related to mathematical knowledge at this growing point, which can arouse students' doubts about material information as much as possible and promote students' thinking and exploration. For example, when Professor Duo, a special teacher, taught "area and area unit", after the students compared the sizes of squares and rectangles, Qian asked, "There are three figures, the first one has 9 squares, the second one has 6 squares, and the third one has 15 squares. Which area is larger? " The students blurted out, "The third figure is the largest because it has the most grids." After a pause, several students found that they were cheated and quickly changed their mouths and said "not necessarily". Teacher Qian asked, "What went wrong with the guess just now?" The student replied, "If the grid of 15 is small and the grid of 6 is large, it may still be the size of 6." Teacher Qian continued to think, "Then how do you think we can compare the sizes of three numbers?" It is concluded that the size of the comparison map should also have a unified area unit.
In the teaching of "area and area unit", the emergence of unified area unit stems from Mr. Qian's ingenious creation of questioning situation. (Author: Chengbei Primary School in Shengzhou City, Zhejiang Province)? □ Editor Deng Shengyuan
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