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单击此处编辑母版标题样式,单击此处编辑母版文本样式,第二级,第三级,第四级,第五级,*,3的倍数的特征,下面哪些数是5的倍数？,58 89 120,145 600 74,哪些数是2的倍数？,5的倍数，个位上的数是5或0。,2的倍数，个位上的数是2、4、6、8或0。,1,2,3,4,5,6,7,8,9,10,11,12,13,14,15,16,17,18,19,20,21,22,23,24,25,26,27,28,29,30,31,32,33,34,35,36,37,38,39,40,41,42,43,44,45,46,47,48,49,50,51,52,53,54,55,56,57,58,59,60,61,62,63,64,65,66,67,68,69,70,71,72,73,74,75,76,77,78,79,80,81,82,83,84,85,86,87,88,89,90,91,92,93,94,95,96,97,98,99,100,在3的倍数上画“”。,1,2,3,4,5,6,7,8,9,10,11,12,13,14,15,16,17,18,19,20,21,22,23,24,25,26,27,28,29,30,31,32,33,34,35,36,37,38,39,40,41,42,43,44,45,46,47,48,49,50,51,52,53,54,55,56,57,58,59,60,61,62,63,64,65,66,67,68,69,70,71,72,73,74,75,76,77,78,79,80,81,82,83,84,85,86,87,88,89,90,91,92,93,94,95,96,97,98,99,100,在3的倍数上画“”。,试一试：,如果一个数不是3的倍数，这个,数各位上数的和会是3的倍数吗？,找几个这样的数算一算。,想想做做：,1.下面的数，哪些是3的倍数？,29 45 51,67 84 96,2+9=11,想想做做：,1.下面的数，哪些是3的倍数？,29,45,51,67 84 96,4+5=9,2+9=11,想想做做：,1.下面的数，哪些是3的倍数？,29,45,51,67 84 96,4+5=9,5+1=6,2+9=11,6+7=13,想想做做：,1.下面的数，哪些是3的倍数？,29,45,51,67,84,96,4+5=9,5+1=6,8+4=12,2+9=11,6+7=13,想想做做：,1.下面的数，哪些是3的倍数？,29,45,51,67,84,96,4+5=9,5+1=6,8+4=12,9+6=15,6+7=13,2+9=11,想想做做：,2.不计算，你能很快说出哪几题的结 果有余数吗？,483,5673,8023,3423,573,想想做做：,在每个数的,里填上一个数字，使这个数是3的倍数。,7,20,12,3,5,里可以填,2、5、8,里可以填,1、4、7、,里可以填,3、6、9,里可以填,1、4、7,想想做做：,4.把下表中9的倍数涂上颜色。,1,2,3,4,5,6,7,8,9,10,11,12,13,14,15,16,17,18,19,20,21,22,23,24,25,26,27,28,29,30,31,32,33,34,35,36,想想做做：,4.把下表中9的倍数涂上颜色。,1,2,3,4,5,6,7,8,9,10,11,12,13,14,15,16,17,18,19,20,21,22,23,24,25,26,27,28,29,30,31,32,33,34,35,36,想想做做：,4.把下表中9的倍数涂上颜色。,1,2,3,4,5,6,7,8,9,10,11,12,13,14,15,16,17,18,19,20,21,22,23,24,25,26,27,28,29,30,31,32,33,34,35,36,9的倍数都是3的倍数吗？,想想做做：,5.从下面选出三张数字卡片，组成一个是3的倍数的三位数。你一共可以组成多少个这样的三位数？,0,5,6,7,
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