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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,*,因数和倍数,3,的,5,倍 是多少,?,复习,:,35=15,试一试,任选其中两题完成,2,的倍数有:,5,的倍数有:,7,的倍数有:,9,的倍数有:,3,的倍数有:,3,,,6,,,9,,,12,,,15,-,2,的倍数有:,2,,,4,,,6,,,8,,,10,-,5,的倍数有:,5,,,10,,,15,,,20,,,25,-,7,的倍数有:,7,,,14,,,21,,,28,,,35,-,9,的倍数有:,9,,,18,,,27,,,36,,,45,-,3,的倍数有:,3,,,6,,,9,,,12,,,15-,2,的倍数有:,2,,,4,,,6,,,8,,,10 -,5,的倍数有:,5,,,10,,,15,,,20,,,25-,7,的倍数有:,7,,,14,,,21,,,28,,,35-,9,的倍数有:,9,,,18,,,27,,,36,,,45-,一个数的倍数的个数是无限的,一个数最小的倍数是它本身,没有最大的倍数。,观察下面几个例子,你能发现这些数的倍数有什么共同的特点吗,?,你能找出,36,所有的因数吗?,试一试,任选其中两题完成,15,的因数有:,16,的因数有:,18,的因数有:,24,的因数有:,36,的因数有:,1,,,2,,,3,,,4,,,6,,,9,,,12,,,18,,,36,。,15,的因数有:,1,,,3,,,5,,,15,。,16,的因数有:,1,,,2,,,4,,,8,,,16,。,18,的因数有:,1,,,2,,,3,,,6,,,9,,,18,。,24,的因数有:,1,,,2,,,3,,,4,,,6,,,8,,,12,,,24,。,36,的因数有:,1,,,2,,,3,,,4,,,6,,,9,,,12,,,18,,,36,。,15,的因数有:,1,,,3,,,5,,,15,。,16,的因数有:,1,,,2,,,4,,,8,,,16,。,18,的因数有:,1,,,2,,,3,,,6,,,9,,,18,。,24,的因数有:,1,,,2,,,3,,,4,,,6,,,8,,,12,,,24,。,一个数的因数的个数是有限的,一个数最小的因数是,1,,最大的因数是它本身。,观察下面几个例子,你能发现这些数的因数有什么共同的特点吗,?,考考你,!,一个数既是,12,的因数,又是,12,的倍数,这个数是(),。,12,因数,10,1,、,2,、,5,、,10,17,1,、,17,28,1,、,28,、,2,、,14,、,4,、,7,32,1,、,32,、,2,、,16,、,4,、,8,48,1,、,48,、,2,、,24,、,3,、,16,、,4,、,12,、,6,、,8,倍数,4,4,、,8,7,7,、,14 ,10,10,、,20 ,12,12,、,24 ,15,15,、,30 ,写出各数的因数或倍数。,
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