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2 2,、,5,的倍数的特征,第,2,章 因数与倍数,课程讲授,新知导入,知识应用,随堂练习,新知导入,试一试,比一比，看谁算得快！,7,1,7,2,7,3,7,4,7,5,7,1,7,2,63,64,65,61,62,7,14,21,28,35,6,12,18,24,30,课程讲授,做一做：,表中哪些数是,5,的倍数？请把它们圈出来。,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,课程讲授,做一做：,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,课程讲授,想一想：,5,15,25,35,45,55,65,75,85,95,10,20,30,40,50,60,70,80,90,100,你圈出的这些,5,的倍数,有什么共同特点？,个位上是,0,或,5,的数都是,5,的倍数。,课程讲授,做一做：,表中哪些数是,2,的倍数？请把它们圈出来。,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,课程讲授,做一做：,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,课程讲授,想一想：,2,12,22,32,42,52,62,72,82,92,4,14,24,34,44,54,64,74,84,94,6,16,26,36,46,56,66,76,86,96,8,18,28,38,48,58,68,78,88,98,10,20,30,40,50,60,70,80,90,100,你圈出的这些,2,的倍数,有什么共同特点？,个位上是,0,2,4,6,8,的数都是,2,的倍数。,课程讲授,看一看：,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,整数中，是,2,的倍数的数叫做,偶数,（,0,也是偶数），不是,2,的倍数的数叫做,奇（,j,）数,。,知识应用,下面哪些数是,2,的倍数？哪些数是,5,的倍数？哪些数既是,2,的倍数，也是,5,的倍数？,1,24 35 67 90 99 15 106,60 75 130 521 280 6018 8100,2,的倍数有：,24, 90 , 106 , 60,，,130 , 280 , 6018 , 8100,。,5,的倍数有：,35,，,90,，,15 , 60 , 75,，,130 , 280 , 8100,。,90,，,60, 130,，,280,，,8100,既是,2,的倍数又是,5,的倍数。,随堂练习,1,下列数中，哪些是奇数？哪些是偶数？,33 98 355 0 123 881,8089 1000 988 565 3678 677,奇数有：,33,355,123,881,8089,565,677,。,偶数有：,98,0,1000,988,3678,随堂练习,2,按要求填空。,（,1,） 两个数位上的数一样，并且是,5,的倍数。,（,2,）,35,既是,2,的倍数，又是,5,的倍数。,（,3,） 既是,2,的倍数，又是,5,的倍数的最小的三位数。,5,5,0,1,0,0,课堂小结,同学们，通过今天的学习，你有什么收获？,我,知道了,
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