Teaching content: Example 5 on page 25 of the sixth grade mathematics textbook published by People's Education Press.
Teaching material analysis: The volume of a cylinder is a section in Unit 3 of the sixth grade math book published by People's Education Press. Cylinders are geometric shapes that are often encountered in daily life. This part of content teaching is conducive to the development of students' spatial concept, and also lays a foundation for further applying geometric knowledge to solve practical problems.
Teaching method: The teaching object of this section is the sixth grade students. Before that, they had learned the volume of cuboids and cubes and had a certain understanding of volume. This lesson is mainly based on their previous work, transforming the volume of cylinders they have not learned into the volume formula of cuboids (cubes) they have learned. In this teaching process, I use the animation micro-course of Onion College to complete this process.
Teaching objective: 1. Explore and master the calculation formula of cylinder volume.
2. Experience the learning method of comparative analysis and inductive discovery through the derivation and discovery process of cylindrical volume formula.
3. Feel the logical relationship between mathematical knowledge and cultivate students' analytical reasoning ability.
Key and difficult points: key: master the calculation formula of cylinder volume.
Difficulties: Understanding the derivation process of a cylinder volume formula.
Teaching preparation: ppt. Volume of Column Items in Animation Micro-course of Onion College (1)
Teaching process:
1. Check the import
1. Guide students to review the volume formula of a cuboid (cube).
The cuboid volume formula = length * width * height, and the unified formula "bottom area * height" can be used for cuboid and cube volume formulas.
2. Show the students a cylindrical object and ask them to find out the bottom, height and side of the cylinder. What are the bottom and sides? How to find its area?
3. Review the area derivation process of the circle, and then use the area formula of the cuboid to derive the area formula of the circle.
2. Explore new knowledge
1. The meaning of cylinder volume.
Review what you have learned before. What is the volume representation? Students think and finally sum up: the size of the space occupied by a cylinder is the volume of the cylinder.
2. Derivation of cylinder volume calculation formula.
By reviewing the volume formulas of cuboids and cubes, we can find that the volume of cuboids and cubes is equal to the bottom area × height.
Student's thinking: There is a fire fighting competition now. Dog egg and hammer made a cylindrical barrel respectively. The bottom area of the cylindrical barrel made of dog eggs is relatively large, while the cylindrical barrel made by Hammer is relatively high. They all say that their buckets are relatively large, so they have to take their own buckets to compete. Now think about how to help them choose.
Students communicate and discuss with each other.
Play the animation micro-lesson of Onion College.
Organize students to watch carefully.
Guide students to draw a conclusion by watching: the volume of a cuboid is equal to the bottom area of a cylinder, the bottom area of a cuboid is equal to the bottom area of a cylinder, and the height of a rectangle is the height of a cylinder.
3. Students write formulas independently, and then discuss and communicate with each other.
Through the process of transforming the volume of a cylinder into the volume of a cuboid, the named students reported that the volume of a cylinder = the bottom area * the height.
Summary: In the process of calculating the volume of a cylinder, if the radius, diameter or circumference of the bottom of the cylinder is already known, then the area of the bottom should be calculated first, and then the volume should be calculated.
blackboard-writing design
Three. Consolidation exercise
1. Onion University Test
2. On page 25 of the textbook, do the first and second questions.