The application problem of finding a number greater than or less than another number is the development of finding a number greater than or less than another number. It is based on finding a number that is more or less than another number. In fact, this kind of problem is still a problem that one number is a few percent of another number, but there is a condition that is not directly given in the problem and needs to be calculated first according to the condition in the problem. Solving the problem of percentage can deepen students' understanding of percentage and improve their ability to solve practical problems with percentage. Because students have fully learned the fractional application problem and simple percentage application problem, according to my previous teaching experience and students' feedback, most students have been able to master the quantitative relationship more accurately. Moreover, fractional application problems and percentage application problems are consistent in solving ideas and methods, and it is feasible to use the ability of knowledge transfer and analogy to guide students to solve such problems.

Second, talk about the difficulties in teaching.

Teaching emphasis: master the method of solving one application problem with more (or less) quantity than another.

Teaching difficulties: understand the specific meaning of the question "how many percent is one number more than the other" and understand the second method.

Third, oral teaching methods

Teaching is the key to success. Whether the teaching methods are used properly or not directly affects the classroom teaching effect. The new curriculum standard points out that we should follow students' cognitive laws and attach importance to cultivating students' ability to acquire knowledge. In order to achieve teaching objectives and successfully complete teaching tasks, I mainly take measures to guide students to rely on old knowledge, explore new knowledge, summarize methods, establish models and consolidate training. Let students actively participate in the learning process. At the same time, I try to guide students to master new knowledge through the following learning methods:

1, independent inquiry method, which allows students to use their existing knowledge and experience to independently explore ways to solve problems.

2. Discuss and communicate, so that students can show different answers after trying to practice. Students can show their thinking in the discussion, and the sparks of thinking collide and make sense clearly. Summarize the general methods to solve such problems and experience the pleasure of success.

3. Drawing comprehension method, through the display of line segment diagram, clarifies the quantitative relationship in the question and reduces the difficulty of knowledge understanding.

4. Summary method: through the summary of problem-solving methods, establish a problem-solving model to solve this kind of percentage problem, deepen the impression, master various learning methods, and improve the ability to analyze, solve and summarize problems.

5, flexible use, through a series of typical and flexible questions, let students master the knowledge of this lesson skillfully and flexibly.

Fourth, talk about the teaching process:

The mathematics teaching mode in our school is "2+2 guidance", and the first "2" in the classroom teaching mode of "2+2 guidance" refers to problem guidance and passing; The second "2" refers to creating situations and paying attention to teaching; According to the characteristics of mathematics, this model emphasizes teachers' "guidance" and students' "practice". The "2+2 Guidance" classroom teaching mode highlights the embodiment of students' dominant position, and requires the whole classroom learning process to be a dynamic and open cooperative learning process in which students actively participate, cooperate in groups and actively explore. Among them, the link of problem guidance and passing standards is the core link of learning plan compilation, and the link of teacher's intensive lecture plays a key role in guiding students to master new knowledge.

According to the teaching content of this lesson, I designed the following links:

Review, awaken old knowledge-question guidance, master new knowledge-elaborate guidance, clarify new knowledge-pass standards, master new knowledge-expand practice, extend new knowledge-class summary, reflection and improvement.

1, review and awaken old knowledge

Because the method of solving problems with fractions is the same as that with percentages, but the results are different, so I designed the same questions as the examples of new knowledge, but the questions are about fractions, which is intended to awaken students' memory of solving problems with fractions and lay a good foundation for learning new knowledge.

2, problem guidance, wake up new knowledge

This link is the core link, emphasizing "learning" and guiding students' learning with problems as the carrier. Provide guidance and explore ideas for students' learning. In this link, I designed five problem situations around new knowledge. First, I grasped the connection point between the old knowledge and the new knowledge, and connected with the three fractions of the review. Under the condition that the known conditions remain unchanged, I changed the "fraction" of the questions into "percentage" for students to try to solve. Because of the old knowledge, students will master it smoothly, and they deeply feel that the old knowledge is an important basis for learning new knowledge. In order to make students deeply understand that "the actual afforestation has increased by a few percent compared with the original plan", guide students to draw pictures to understand, and also make students feel that the method of reviewing scores to solve problems is the same as the method of solving problems by percentage, but the results should be expressed by percentage.

The difficulty of this lesson is the second problem-solving method and the third problem guided by the problem. Students first learn and understand by themselves around the self-study tips in the tutoring plan, combined with their own knowledge base and learning ability, and then communicate and show on this basis, which is conducive to the complementarity of students' thinking and makes the problems explored and solved more comprehensive. It can not only give full play to the role of student groups, but also cultivate students' sense of cooperation. Here mainly refers to the display and communication within the group, showing the self-study results one by one, exchanging ideas and methods with each other, and correcting fallacies and deviations with each other. The team leader is responsible for collecting and sorting out the controversial issues that cannot be solved within the team.

Then it is to guide students to summarize the problem-solving methods of this kind of percentage problems, establish models and deepen their impressions. Finally, let the students talk about how people express their increase and decrease in real life and feel the close relationship between mathematics and life.

3. Strengthen teaching and clarify new knowledge.

After summing up the solution to the problem, it is still the original known conditions, but the question becomes "How much less is the original planned afforestation than the actual afforestation?" Ask students to try to solve it in two ways. Because the percentage in the above question is116.7%-100%, the percentage in this question is less than100%, and students will have questions. What if 100% cannot be reduced? (2) exquisite instructions. In view of the exposed problems, guide students back to the understanding level of basic knowledge and give incisive explanations. Promptly enlighten, guide and enlighten students to help them solve problems. Through inspiration, guide students to sum up and reflect on their own ideas of exploring and solving problems, let students think and form * * * knowledge, so as to complete the formation of knowledge in an orderly and systematic way.

4, through the standard, master new knowledge.

Passing the customs and reaching the standard is also one of the two core links in teaching. The design of the topic of "Pass the Customs" generally appears in the form of problem groups, which can meet the needs of all kinds of students, conform to the cognitive rules of students and promote the development of students' personality. So, according to the teaching content, I designed the basic exercises, one by one, looking for the unit "1", judging the questions, and calculating and expanding the exercises according to the pictures. Deepen students' consolidation and flexible application of knowledge, and finally achieve proficiency in new knowledge. In this link, not only students should practice, but also teachers should supplement, correct and emphasize the problems exposed by students again in the process of practice, constantly improve students' mastery of new knowledge, and realize the rise from perceptual knowledge to rational knowledge.

5. Expand practice and extend new knowledge.

The expanding exercise comprehensively uses the knowledge of squares and circles and the knowledge learned in this class, which is more comprehensive. It is not only an investigation of students' comprehensive ability, but also the cultivation of students' knowledge expansion ability.

6, class summary, reflection and improvement

Classroom summary middle school students report their knowledge, the gains in learning methods, the shortcomings and efforts of this class, aiming at guiding students not only to learn to summarize, but also to learn to reflect, so as to improve faster and gain more in the future learning path.