圆的认识教学设计张彩(国外英文资料).docVIP

圆的认识教学设计张彩(国外英文资料) Students, we not only use circles to decorate our lives Some of the features of the circle are skillfully used for life (two) operation inquiry Understand new knowledge 1, a discount Center of cognition (1) ask the students to prepare a circle picture prepared by the teacher Fold and open After another direction, fold it again Look, how many creases Do you have? Does it intersect? Fold it again Tell me what you found Students communicate with each others discoveries (all creases meet at one point This point is at the center of the circle (2) the teacher reveals: we call it the center of the circle. With the letter / (3) after courseware demonstration The students mark the center of the circle themselves 2, Lian Yilian Radius and diameter of cognition (1) the line segment that connects the center of the circle and any point on the circle is called the radius of the circle Use the letter gamma to indicate (2) courseware demonstration; (3) ask the students to find the key words in the definition (4) the teacher explains the circle, the circle, the inside and the circle (5) students draw a radius in their circle And marked with letters (6) think about how many radii can be drawn in the same circle What does the length of these radii have to do with it? By thinking, discussing, and measuring practically, students recognize that there are countless radii in the same circle All the radii are equal in length (7) the line segment that passes through the center of the circle and has both ends on the circle is called the diameter of the circle Use the letter d to indicate (8) courseware demonstration; (9) students refer to each other in diameter And draw a diameter in your circle (10) think about how many diameters there are in the same circle Are all diameters equal in length? By thinking, discussing, and measuring practically, students recognize that there are countless diameters in the same circle All diameters are equal in length 3, one to one Grasp the