圆的周长教案（Circle perimeter lesson plan）.docVIP

圆的周长教案（Circle perimeter lesson plan） Circumference Teaching target 1, make the students know the circumference of a circle, to understand the meaning of pi. 2, through practical operation, to explore the perimeter of the circle formula, and can use it to solve simple practical problems. 3, to train students to observe, explore and generalize their abilities while penetrating dialectical materialism and ideological education; and combining the story of Zu Chongzhi, an ancient mathematician in China, to educate students in patriotism. Teaching emphasis A method for calculating the circumference of a circle is developed to investigate the characteristics of a circle. Teaching difficulties Accurately measuring the circumference of a circle, to understand the meaning of PI Teaching preparation Round pieces of paper, round objects, lines, computers, rulers teaching process Draw a rectangle and a square on the blackboard Teachers, who can use crayons painted rectangular and square perimeter, and represented by the letter out of the perimeter of the formula, the other students look carefully. Born on the blackboard, The teacher is finished. Please go back. The students see, are they both right?, Born, yes Teacher, what is the perimeter of a rectangle?, Life, length and width The circumference of a teacher is several times as long and as wide as that of a teacher Raw, two times Division, what about the square? Life is related to the length of the mouth. The circumference is four times the length of the side Teacher, it seems that everyone has a strong grasp of the old knowledge, the teacher is very happy. Teacher, these are what we have learned before. Today, the teacher will take you to learn new content. Show courseware On Sunday, Xiao Ming went to play in the park. He wanted to know how many meters he would ride around. How would you like to help him?, Be willing to What shape is the trajectory formed by riding a circle of Xiao Ming? Raw, round, Division, that requires ri