First, contact with real life, promote knowledge transfer and stimulate interest.
Primary school students' thinking is mainly visual. In teaching, we should give full consideration to the characteristics of students' physical and mental development, combine students' life experience and existing knowledge, design interesting and meaningful activities, stimulate students' interest in learning and build a bridge of students' cognition.
For example, when teaching scale, I show students photos and campus plans to compare them with the actual things. Familiar life phenomena have aroused students' strong desire to explore. Through analysis, comparison and discussion, students realize that the shapes of objects and pictures are the same, but the sizes are different, and there is a certain proportional relationship between them. Photos and floor plans are made in a certain scale, so as to understand the connotation of scale. In the teaching of "Understanding Circle", I started with why the wheels of bicycles and cars should be made into circles instead of triangles, squares and pentagons. Students are attracted by familiar phenomena. In order to find the answer, they started experiments and taught themselves textbooks, and soon found the theoretical basis and mastered the characteristics of circles. At this point, I didn't stop there. I continued to let them think about what other objects in life are made into circles, and explain why they are made into circles with what they have learned, so that mathematics knowledge can be linked with life again. For example, in the application teaching of proportional distribution, I designed two questions: Is it fair to distribute 100 hectares of land to Dongfeng Village 1 to five villagers' groups for farming? Is it reasonable to divide the land into five parts and plant onions, ginger, garlic, vegetables and rice respectively? These problems are closely related to students' lives. They know that the land should be divided according to the number of people and the crops should be planted according to the demand, so they know that it is sometimes unreasonable to divide the land equally, and a new distribution method must be decided according to the actual situation. This naturally produces "proportional distribution", and its connotation is self-evident. Let them realize that there is mathematics everywhere in life, mathematics is around us, and we live in a real world full of mathematical information. This kind of teaching conforms to children's cognitive law, which can encourage students to learn to observe and understand things around them from a mathematical point of view and effectively promote the transfer of knowledge.
Second, strengthen one's own experience, break through teaching difficulties and internalize knowledge.
A class, no matter how clearly the textbook is written and how clearly and thoroughly the teacher speaks, can only be completed by students' constant perception and experience in practice.
In order to help students understand the concepts of "meeting", "two places", "walking in opposite directions" and "meeting", I led the students to stand in two rows on the playground and asked them to actually walk according to the teacher's instructions. Students quickly understood these concepts during the stop-and-go, and when they returned to the classroom to explain the "encounter problem", it was easy to solve it. "Volume" is a difficult concept to understand. When teaching this course, I asked students to prepare two cups of the same size, pour the same volume of water into them, put an iron lock in one cup and a nut in the other, and let them observe the change of water level and think about why there is such a change. Through observation, students understand that the water level rises because objects occupy part of the space. When the iron lock occupies a large space, the water level rises high, while when the nut occupies a small space, the water level rises less, so it is understood that the space occupied by the object is called the object volume. This experimental method is much better than teachers' simple narration and students' mechanical recitation. For another example, in the teaching of cone volume, because students tend to ignore the condition that the base heights of cylinders and cones are equal, in order to remove obstacles, I specially prepared several groups of empty cylinders and cones with different base heights for students to experiment. Because students ignore the condition of equal base height, they can't get V= 1/3sh. Is the conclusion in the book wrong? The students were lost in thought. Through analysis, discussion and finding out the reasons, students suddenly realize that the conditions of equal bottom and equal height are ignored, and the teaching difficulties are overreached in students' personal experience.
In addition, according to the teaching content, I also ask students to calculate the water and electricity charges at home, deposit interest, how many tiles are needed for decoration and so on. In short, as long as there is suitable content, I try to let students experience it personally. Students also find learning simple, practical and interesting. This kind of teaching can establish students' concept of popular mathematics, conform to children's cognitive law, and help students internalize knowledge.
Third, adhere to language expression, promote the development of thinking and exercise intelligence.
In teaching, we should not only pay attention to whether students can "do" but also pay attention to whether students can "speak".
Students are required to express themselves in their own language on the basis of experience. For example, when teaching the basic properties of decimals, by observing the equation 0.1= 0.10 = 0.100, let students discuss: "What has changed at the end of decimals from left to right?" "Looking from right to left again, what changes have been made to the decimal?" "What pattern did you find?" "How to summarize this rule?" Wait a minute. This provides students with opportunities to express their thoughts, and only by letting them express themselves can they expose the defects in the thinking process. At this time, teachers should guide the situation according to students' expressions, which can effectively promote the development of students' thinking. When teaching "the nature of quotient invariance", students summed up the law that "the dividend and divisor expand or shrink by the same multiple at the same time, and the quotient remains unchanged". At this time, students can show the formula 6 ÷ 2 = (6× 0) ÷ (2× 0) = 3 to judge whether it is right or wrong. Students soon found that 2×0=0, but the divisor can't be zero, and the original summary rule is not strict, so we should add the condition of "not containing zero" to improve it. Teachers should encourage and guide students' speeches, avoid depriving them of the right to speak poorly, and give them enough time to speak.
Fourth, carry out multiple evaluations to build students' self-confidence and stimulate students' emotions.
One more measuring ruler will lead to one more good student. Good students are not beaten and scolded, but praised. For example, when teaching the understanding of cylinders, I ask students to explore the characteristics of cylinders through observation and experiments. Sheng 1 said: "A cylinder is a figure composed of three faces." I immediately praised his observation ability. Student 2 found the height of the column by comparing with my deskmate. I patted him on the shoulder and said, "Your discovery is really great." Student 3 came up with a unique method to verify whether the top surface and the bottom surface are equal. I commend him for his flexible thinking and unique imagination. When student 4 gesticulated with his hand to ask whether an inclined figure with equal upper and lower circles (referring to an inclined cylinder) was a cylinder, I excitedly held his hand and said, "I didn't expect this question you asked!" You are really a clever boy. " I made a mistake and blushed when I summarized the definition of cylinder height. I immediately said, "Although your answer is wrong, your spirit of daring to speak and express your thoughts is worth learning."