Reflections on the teaching of "Knowing Numbers within 10,000" in Senior Two. This lesson is based on understanding numbers within 1000. Although I have some knowledge and experience in counting, reading, writing and how to analyze a number within 1000, the concept of 10000, including numbers greater than 1000 and less than 10000, is actually unfamiliar to students. So on the basis of mastering the students' existing knowledge and experience, I designed some teaching scenes to break through this key and difficult point.

First, experience the process of exploration and feel the fun of mathematics. ? When I introduced the concept of Wan, I made some wall charts, from a small square to a small square, from ten small squares to a small square, and from ten sides to a large solid square, so that students can gradually understand and perceive that 10 is ten, 10 is one hundred, and 10 is10.

? Second, from concrete to abstract, gradually develop the sense of numbers. ? Primary school students' thinking is mainly based on concrete images, and abstract thinking cannot be separated from the support of images. When mastering the concept of numbers, they need the guidance of physical objects. So in teaching, I designed several small squares to let students experience the change of decimal relations, which is the most vivid stage of experience. Then, using the semi-abstraction of the counter, let the students convert the numbers one by one, ten by one, one by one and eleven by one. After the establishment of the abstract concept, it needs to be strengthened and consolidated, so after getting 10 thousand on the counter, I designed a teaching scene to guess and think. For example, I took out a page myself and asked the students to guess "How many words did the teacher type on this page?" The enthusiasm of the students is very high. Some guessed 500, and the teacher told him "you are too short", while others guessed 1200 and said "you guessed a little more". Finally, tell them that there are 1000 words here, and then let them imagine how many pages there are in 10 thousand words. Why? The enthusiasm of the students was fully mobilized, and they realized that this printing needed 10 sheets of paper. Then I provide them with some physical objects to imagine how thick 10 thousand pieces of paper are, how much a grain of rice is, how long 10 thousand meters are, and so on. This not only breaks through the difficulties, but also cultivates students' self-constructed learning attitude. In the following digital reading and writing teaching, not only the pictures of squares are displayed, but also students can observe how many squares there are in a * * *, and then the counter dials the number and tries to read and write this number, which fully embodies the close combination of shape, number and shape, and lays a solid foundation for students to form the concept of numbers and understand the composition of numbers. Numbers within tens of thousands are a difficult problem to solve. When the number is large, especially when it reaches 1 after entering1,it has always been a difficult point for students to learn. Therefore, we need to rely on the support of specific images. In teaching, I use a counter to make students think about what will happen if one more bead is added at a key place. What number should be next and why? The difficulty will be solved.

Third, from life, experience the connection between mathematics and life. ? In this lesson, I introduce a picture of a school's recess exercise activity with examples from life, so that students can understand the number of students in the imaginary school. In class, students can read several real-life information collected by teachers, such as the number of seats in the cinema and the height of Mount Everest, which arouse students' concern and love for the real world and realize the role of numbers within 10,000 in life. They can express things and exchange information with big numbers within 10 thousand, which not only cultivates the sense of numbers.