Teaching content: Qingdao version of five-year primary school mathematics textbook, second grade, Volume II 104, page "How to find several times a number". Teaching objectives 1. Understand the meaning of "several times more (less) than a number" and master the two-step calculation method of "several times more (less) than a number". Will use the line chart to analyze the quantitative relationship and determine the problem-solving ideas. 2. Through observation, comparison, discussion and other activities, cultivate students' preliminary generalization ability and problem-solving ability, and learn to express and communicate in mathematical language. 3. In the process of mathematics learning, stimulate students' interest in learning, cultivate their desire to explore and feel the order of mathematical thinking. Teaching process 1. Create situations and introduce new lessons. Teacher: Students, have you ever seen shells? What shells have you seen? Beautiful shells are as beautiful as handicrafts. Look, what is this? (Showing handicrafts made of shells) Health: Big rooster, naive pig, cute hedgehog ... Teacher: There are still many math problems hidden in it. Second, analyze and solve the problem of "several times more than several times". (1) Find information and ask questions. Teacher: After careful observation, what mathematical information did you find? Health: It takes 42 shells to make a hedgehog. Health 2: The number of shells used to make a big hedgehog is six times that of a small hedgehog, 18. Teacher's blackboard writing: Little Hedgehog 42-shell Big Hedgehog is 6 times more than Little Hedgehog 18 Teacher: Who will tell us the information again? Health: It takes 42 shells to make a small hedgehog, and the number of shells to make a big hedgehog is 6 times that of a small hedgehog, 18 shells. Teacher: What math questions do you ask? Health: How many shells does it take to make a big hedgehog? Teacher: Are there any other questions? Teacher: Let's talk about information and questions again. Health: It takes 42 shells to make a small hedgehog, and the number of shells to make a big hedgehog is 6 times that of a small hedgehog, 18 shells. How many shells does it take to be a big hedgehog? (2) Organize information and analyze the quantitative relationship. 1, explore the sorting method. Teacher: This question is too informative. Is there any good way for students to rearrange the information and questions so that everyone can easily see the relationship between them? Health: Draw a circle. Health: Write it on a piece of paper. Health: Draw a line segment. Teacher: The students have come up with so many good methods! Now try it in your favorite way and see who arranged it simply and clearly, so that everyone can see the meaning at a glance. Student organization information. 2. Exchange reports to reflect diversity. Health 1: health 2: health 3: health 4: health 5: 3, optimize the method and standardize the drawing method of line segment diagram.