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状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,第,1,课时 最小公倍数（,1,）,R,五年级下册,中牟县晨阳路学校,李伟娟,学习目标,学习重难点,1.,使学生理解公倍数，最小公倍数的概念。,2.,掌握求两个数最小公倍数的方法，并能正确地求两个数的最小公倍数。,求两个数的最小公倍数的方法,复习旧知,什么是倍数？,复习旧知,什么是倍数？,在整数除法中，如果商是整数,而没有余数，我们就说被除数是除数,的倍数。,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,一个数最小的倍数是它本身没有最大的倍数。,01,一个数倍数的个数是无限的。,02,倍数的特点,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,探究新知,分别写出,4,和,6,的倍数,4,的倍数：,6,的倍数：,你发现了什么？,4,，,8,，,12,，,16,，,20,，,24,，,28,，,32,，,36,，,40,，,6,，,12,，,18,，,24,，,30,，,36,，,42,，,12,12,24,36,24,36,公倍数：,几个整数公有的倍数叫做这几个数的,公倍数,。,4,的倍数：,6,的倍数：,你发现了什么？,4,，,8,，,12,，,16,，,20,，,24,，,28,，,32,，,36,，,40,，,6,，,12,，,18,，,24,，,30,，,36,，,42,，,12,12,24,36,24,36,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,4,的倍数,6,的倍数,12,，,24,，,36,，,6,，,18,，,30,，,42,，,4,，,8,，,16,，,20,，,28,，,32,，,40,，,最小公倍数：,几个整数的公倍数中最小的数叫做这几个数的,最小公倍数,。,求,6,和,8,的公倍数和最,小公,倍数,。,2,求最小公倍数的步骤有哪些呢？,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,6,的倍数：,6,，,12,，,18,，,24,，,30,，,36,，,42,，,48,，,8,的倍数：,8,，,16,，,24,，,32,，,40,，,48,，,找出相同的因数。,它们的公倍数为,24,，,48,，,最小公倍数为,24,。,做题步骤,1,.,分别找出两数的倍数,2,.,找出两数的公倍数,3,.,从公倍数中选出最小的公倍数,巩固练习：,请你找出,6,和,9,的倍数、公倍数并圈出它们的最小公倍数。,6,的,倍数：,9,的,倍数：,6,，,12,，,18 ， 24,，,30,，,36，42,，,48，54 ,9,，,18，27,、,36，45,54,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,9,的倍数,6,的倍数,6,，,12,，,24,，,30,，,42,，,48 ,18,，,36,，,54,9,，,27,，,45,最小公倍数,发现公倍数与最小公倍数之间有什么关系了吗？,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,公倍数和最小公倍数的关系：两数的公倍数一定是这两个数最小公倍数的倍数。,最小公倍数,1.,几个整数公有的倍数叫做,这几个数的,公倍数,。,2.,几个整数的公倍数中最小的数叫做,这几个数的,最小公倍数,。,小,结,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,1.,选择题。,达标检测,（,1,）一个数的（ ）的个数是无限的。,A.,因数,B.,倍数,C.,最小公倍数,（,2,）,34,是,17,和,2,的（ ）。,A.,因数,B.,最大公因数,C.,最小公倍数,B,C,B,（,3,）因为,60,是,10,的倍数，也是,5,的倍数，,所以,60,是,10,和,5,的（ ）。,A.,最小公倍数,B.,公倍数,C.,最小公因数,3.,求下列每组数的最小公倍数。,8,和,106,和,156,和,9,40,30,18,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,4.,写出每组分数的两个分母的最小公倍数。,和,和,和,12,24,18,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,课后作业,1.,课后习题,P71,第,3,、,5,、,8,题；,2.,完成练习册本课时的习题。,
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