Understand the meaning of lateral area and surface area of cylinder. Ability goal: Derive and master the method of calculating the lateral area and surface area of cylinder independently through operation, and solve practical problems. Emotional goal: to experience the harvest of success and the pleasure of cooperation. Teaching emphasis: lateral area teaching of understanding cylinders by hands. Difficulties: the diversity of the development diagram of the cylinder side and the ability to connect the development diagram with all parts of the cylinder. Formulas for calculating the lateral area and surface area of a cylinder are derived. Teaching aid preparation: computer animation display of cylindrical surface. Preparation of learning tools: rectangular paper (square), parallelogram paper, scissors and cylindrical paper box. First, create a situation to stimulate interest. Take out the cylinder model, who can tell which parts the cylinder is made of? Think about how to prepare the material for this cylinder. (Students may say to make two round bottoms and one edge. ) So guess how the side is made? (Tell your own guess) 2. Explore independently and find problems. The transverse area of cylinder 1 is studied. Use the materials in your hand independently and verify the conjecture in your favorite way. There may be many possibilities for unfolding in the way you like, such as cutting obliquely, or some students may roll a square paper roll to the side of the cylinder. 3. Observe and compare the relationship between each part of the unfolded figure and the cylinder. 4. Can you calculate the area of mass sending with existing knowledge? 5. Panel report. (Choose a student to paste the expanded graphics on the blackboard. ) key feeling: if the side of the cylinder is unfolded along the height, it is a rectangle. (The emphasis here is on cutting along the height. What does this rectangle have to do with which side of the cylinder? (The length of a rectangle is the circumference of the bottom of a cylinder, and the width of a rectangle is the height of a cylinder) Area of a rectangle = lateral area of a long and wide cylinder = circumference of the bottom × height S-side = c× h If the radius of the bottom is known as r, the lateral area formula of a cylinder can also be written as: S-side =2∏r×h Teacher: If the cylinder is a parallelogram, is it also applicable? Students begin to operate and write verification, and come to the same conclusion. This may happen because some students just cut it in their favorite way. At this time, students who have drawn a parallelogram can introduce his cutting method, and then everyone will take out the prepared cylindrical paper box and unfold it like this. ) Study the cylindrical area of 1. Now, please try to find out what material your cylinder is made of. Students measure and calculate the surface area. It is concluded that the surface area of the cylinder = the side area of the cylinder+the bottom area × 2 3. Animation: the unfolding process of cylinder surface; Consolidate exercises; Summary of the whole class; Blackboard design: surface area of cylinder = rectangular area of length × width; Lateral area of cylinder = perimeter of bottom × height → S side = surface area of ch cylinder = side area of cylinder+bottom area ×2.