图形放缩PPT下载北师大版六年级的数学下册 (2)课件

单击此处编辑母版文本样式,第二级,第三级,第四级,第五级,*,图形的放缩,北师大版六年级数学下册课件,一张贺卡的长是,6,厘米,宽是,4,厘米。,下面是笑笑、淘气、小斌在方格纸上画的这张贺卡的示意图。谁画得像呢？（每格边长为,1,厘米）,我画的图,宽,1,厘米相当于实际的,4,厘米,长,1.5,厘米相当于实际的,6,厘米。,卡片的长和宽的比是,6:4,也就是,3:2,所以,我画的图长和宽的比是,3:2,。,只要长比宽长一些就行。,只有长和宽都按相同的比来画,画得才像。,4cm,6cm,3cm,2cm,2,6,0,1,2,3,4,5,6,7,8,9,10,1,3,4,5,7,8,9,10,11,12,A,B,C,D,E,F,如果,A,点用（,0,，,2,）点表示，那,么,B,、,C,、,D,、,E,、,F,怎么表示？,思考：,B,（,5,，,6,）,C,（,3,，,2,）,D,（,5,，,3,）,E,（,5,，,1,）,F,（,4,，,0,）,如果用（,X,Y,）来表示一个点，那么（,2X,Y,）表示什么？,想一想：,2,6,0,1,2,3,4,5,6,7,8,9,10,1,3,4,5,7,8,9,10,11,12,那么（,X,2Y,）呢？,鱼变长了！,2,6,0,1,2,3,4,5,6,7,8,9,10,1,3,4,5,7,8,9,10,11,12,(2X,2Y),表示什么：,口答：,鱼变宽了！,2,6,0,1,2,3,4,5,6,7,8,9,10,1,3,4,5,7,8,9,10,11,12,鱼变大了！,怎样将一个图形放大呢？,想一想：,右图是一只可爱的小猫乐乐,请将表示乐乐轮廓的点的数对填在下面。,A(,2,0,)B(,4,0,)C(,6,2,)D(,6,6,),E()F()G()H(),I()J(),5,8,4,6,2,6,1,8,0,6,0,2,2,6,0,1,2,3,4,5,6,7,8,9,10,1,3,4,5,7,8,9,10,11,12,吃,2,6,0,1,2,3,4,5,6,7,8,9,10,1,3,4,5,7,8,9,10,11,12,2,6,0,1,2,3,4,5,6,7,8,9,10,1,3,4,5,7,8,9,10,11,12,2,6,0,1,2,3,4,5,6,7,8,9,10,1,3,4,5,7,8,9,10,11,12,通过本课学习，你学会了什么？,