It is very important for students to experience life personally. Only by experiencing in life can we better perceive our mathematics and make good use of it, especially the abstract and difficult length like "kilometer". When preparing lessons, I want to complete the teaching activities of this class through practical activities. I plan to let students experience the length of 1m, 10m and 100m in the "hand in hand" activity, and infer the length of 1000m from it. Take a walk and feel the actual length. Therefore, I divide this lesson into three parts.
First, check the import.
Review the length units of meter, decimeter, centimeter and millimeter, and let the students use gestures to further consolidate their spatial concept of the learned length units. Then ask questions. What unit do you need to choose to show the distance from your hometown to Jinjiang? Students think it seems impossible to choose these length units, so they introduce new courses.
Second, experience perception.
(1) Hand-in-hand activity: Let students think and experience hand in hand on the playground, from small to large, step by step, and let students' behavior and thinking approach the large number we need step by step.
1, a classmate opens his hand about 1 meter long. How many people does it take to stand hand in hand in a row about 10 meters long?
The whole class stands in a row hand in hand. Is it 100 meter long?
3. How many students stand hand in hand in a row, about 100 meters long?
4. Walk along the route of 100 meters, and the circle of 10 is 1000 meters, which can also be expressed as 1 km. That is, 1km= 1000m, which means 1km = 1000m in letters.
(2) Walking: It is really long for students to experience kilometers through walking.
1. How many steps does it take for students to walk along the meter scale of 1 meter?
2. How many steps does it take to reach 10 meter? 100 meter? 1000m?
3. You can go to the playground after class and walk back and forth 10 to see how long it takes.
Through experience, students here fully expand the depth and breadth of knowledge on the basis of the original concept of knowledge, develop students' spatial imagination and practical experience, enable students to form a perceptual understanding of how long a thousand meters is, and at the same time flexibly use meters and kilometers in their lives.
Third, the application in life and the exchange of units. Students often use kilometer units in their lives, but some students can't understand the actual meaning of kilometer after learning, which leads to mistakes in using and addressing units. Therefore, the focus of teaching is to let students understand the measurement significance of kilometers. Therefore, in class, we can make use of the phenomenon that the open hand is about 1 meter, which is convenient for students to unfold intuitively and extend to kilometers step by step.
Some mathematical knowledge must be felt and experienced by students, not too much trouble. Students can't use knowledge flexibly when doing problems because they don't understand. From here, I further realize that students should pay attention to learning in real life situations and feel the connection between teaching and life in order to enhance their enthusiasm for learning mathematics.