How to effectively apply information technology in junior high school mathematics teaching? The new curriculum standard advocates the use of information technology to present teaching content that is difficult to present in previous teaching, and realizes the organic integration of information technology and mathematics. This approach is to integrate information technology into the mathematics curriculum and "integrate algorithms into all relevant parts of the mathematics curriculum" in content, making information technology a necessary tool for teaching and learning mathematics curriculum, and mastering information technology a necessary condition for learning or teaching mathematics curriculum well. Teachers use computers to comprehensively deal with teaching needs such as graphics, numbers, animations, sounds and backgrounds, making them easy to understand and master, enabling students to use computers to extract information, interact with feedback and learn independently, and making learning ability, exploration ability, innovation ability and problem-solving ability in mathematics become the development direction of students' personality potential. The application of information technology in subject teaching is an inevitable requirement for us in the new curriculum. How to treat information technology, how to properly integrate information technology with subject teaching, and how to use multimedia teaching to get many beneficial inspirations. 1. Information technology is intuitive, which can break through the limitation of vision, observe objects from multiple angles, highlight key points, and help to understand concepts and master methods. In the class of "Translation and Rotation", the author of this paper designed such a problem: Translation and rotation not only appear in amusement parks, but also have many translation and rotation phenomena in our daily life. Let the students combine their own feelings and real life to judge which of the following pictures are translation movements and which are rotation movements. There are several translation and rotation phenomena in life on the screen. (The ladder moves up and down, the windmill rotates ...) The scenes played in the video are often seen by students in their daily lives, such as car movement, yo-yo rotation, windmill rotation, sliding window movement, elevator movement and so on. These scenes are familiar in students' life. Maybe they don't care about these phenomena at ordinary times, let alone think that these phenomena can be related to our mathematics knowledge today. Through the playing of this video, they have deepened their understanding of these two sports modes. Then the teacher asked, "Who can tell me what translation and rotation phenomena you have seen in your life? Because of the actual video of translation or rotation displayed on the front screen, the students told many phenomena of these two sports modes in life. Second, information technology is illustrated, which can mobilize students' emotions, attention and interest from multiple angles. For example, when teaching the vertical diameter theorem, students didn't understand the proof of the vertical diameter theorem in the textbook, so I made a FLASH animation. After the animation demonstration according to the proof process in the textbook, many students can try to prove it, which is similar to the proof process in the textbook. Using the fast drawing, animation, video, sound and other functions of multimedia computer, we can quickly simulate some processes of invention and discovery, so that the "discovery method" teaching which is difficult to realize in traditional teaching may be implemented frequently. For example, in the teaching of "similarity", I made a courseware with a geometric sketchpad and drew two similar figures. Under my guidance, students quickly find out the relationship between the corresponding edge, the corresponding angle and the distance from the corresponding vertex to the center by using the measurement function of the software, and then observe the changes of the graph by adjusting the position of any vertex or similar center, so that students have a deeper understanding of this content. Because this section is no better than other chapters, its graphics can be drawn as you want, and it takes a certain amount of time, so the teaching effect of the conventional mode will definitely not be good. Thirdly, information technology is dynamic, which can effectively break through teaching difficulties and help to embody concepts and processes. For example, in the ninth grade "Parabola" class, students' understanding of parabola is a smooth curve, but we use multimedia to play a game between the Rockets and the Lakers to show the basketball trajectory of basketball player Yao Ming when shooting, so that students will have a more intuitive understanding of parabola. Because of the computer demonstration, the method is novel, the students pay attention and leave a deep impression on them, and the teaching effect is obvious. Fourthly, information technology is interactive, which allows students to participate and learn more actively, and helps students form a new cognitive structure by creating a reflective environment. As we all know, in the traditional teaching process, everything is decided by the teacher. The teaching content, teaching strategies, teaching methods, teaching steps and even the exercises that students do are all arranged by the teacher in advance, and students can only passively participate in this process, that is, they are in the state of being indoctrinated. In the interactive learning environment such as multimedia computer, students can choose what they want to learn according to their own learning foundation and interests, and they can choose exercises suitable for their own level. If the teaching software is better, you can even choose the teaching mode. For example, the bisection theorem of parallel lines is an important knowledge point in plane geometry, an extension of congruent triangles, parallelogram and trapezoid, and the basis for learning the proportion of parallel lines. Correctly understanding the theorem of parallel lines bisecting line segments is the key to teaching, and learning a ruler to bisect known line segments is also the focus of this section. The content and proof method of the theorem are given directly in the textbook. If traditional teaching methods are used to explain, mechanical steps and static graphics give students a boring feeling, which can only show students the conclusion of knowledge and is not convenient to reveal the process of problem inquiry. In this way, students only know the bisection theorem of parallel lines but don't know why, and the cognitive structure of students' knowledge is broken, which is not conducive to the cultivation of ability. In order to let students participate in the process of exploring problems and correctly understand the proportionality theorem of parallel lines, I made a courseware with the specific content of this textbook. I use the calculation, animation and hiding functions of the courseware to strengthen students' perceptual knowledge, guide students to participate in the exploration of problems, cultivate students' ability to analyze problems, and let students measure the length of line segments on the computer, calculate the ratio of line segments, and then verify whether the ratio of line segments is equal. In addition, students can easily "discover" two inferences of this theorem, that is, its two variant graphs, by moving the positions of line segments in the graph in parallel. This teaching method design highlights the students' dominant position and experimental consciousness of exploration and observation. From the general to the special, from the image to the abstract, through such experiments, observations, guesses and confirmations, students are guided to give proofs, so that problems that are difficult to explain can be solved in students' experiments. Fifth, information technology is complementary, which can expand general experiments through multimedia experiments and cultivate students' exploration and creativity through the reproduction and simulation of real scenes. For example, when the middle line is open, you can design the following courseware for students to experiment with the geometric sketchpad. Draw an arbitrarily adjustable quadrilateral ABCD and connect the midpoints of the quadrilateral in turn to get an inscribed quadrilateral EFGH. Experiment: (1) drag the quadrilateral ABCD at will to observe what the inscribed quadrilateral is (parallelogram); (2) When the quadrilateral ABCD is rectangular, observe what figure the inscribed quadrilateral is (diamond); (3) When the quadrilateral ABCD is rhombic, observe what figure (rectangle) the inscribed quadrilateral is; (4) Adjust the quadrilateral ABCD to make its diagonal lines equal, and observe what figure (diamond) the inscribed quadrilateral is; (5) When adjusting the quadrilateral ABCD to make its diagonals perpendicular to each other, observe what figure (rectangle) the inscribed quadrilateral is; (6) When adjusting the quadrilateral ABCD so that the diagonals are perpendicular to each other, observe what figure (square) the inscribed quadrilateral is. Under the guidance of the teacher, students make bold guesses and proofs through the above experiments, and finally come to a conclusion. Using the dynamic display of geometry sketchpad, students can solve a difficult problem in the experiment. Sixth, information technology has a large capacity, which can save space and time and improve teaching efficiency. Teachers have this experience: in order to save time in writing blackboard books in class, a large number of notes are prepared before class, and the contents of blackboard books are written one by one; In order to increase the amount of classroom exercises, all kinds of exercises are copied on the blackboard. Its disadvantage is that it increases the workload of teachers. If the weather is bad, the students sitting in the back row can't read the words on the blackboard clearly, which will affect the teaching effect. For example, in the Data and Chart Review Course, you can use multimedia with a large amount of information for topics related to statistical tables and chart design. It is difficult for students to accept the lack of information. CAI's intervention in classroom teaching has solved this problem well. Because multimedia technology is "dynamic", it transmits a large amount of information, with high speed and strong interactivity, which makes high-density and large-capacity training and information exchange possible. In this way, teachers can carefully organize students' learning activities in class and optimize teachers' teaching and students' learning. Students will have a more intuitive understanding of parabola when shooting in Yao Ming. Because of the computer demonstration, the method is novel, the students pay attention and leave a deep impression on them, and the teaching effect is obvious. In short, the role of multimedia information technology in mathematics teaching can not be underestimated, and its role in assisting students' cognition is better than any previous technical means. Proper use of information technology has played the role of "moving one child and living everything", giving full play to the best efficiency of classroom teaching, optimizing classroom teaching structure and improving classroom teaching efficiency can reduce the learning burden, make students become passive and active, and meet the needs of modern education to cultivate innovative talents. Applying multimedia information technology to classroom teaching objectively and reasonably, and actively exploring the integration method of multimedia information technology and classroom teaching are the concepts that modern teachers should actively change in teaching activities.