五年级6.2-2、3、5的倍数的特征市名师优质课比赛一等奖市公开课获奖课件.pptx

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,*,2,、,3,、,5,倍数特征,情境导入,探究新知,课堂小结,课后作业,课堂练习,青岛版（六年制）数学 五年级 上册,因数与倍数,6,第1页,圆圈舞,叠罗汉,交谊舞,你能提出什么问题？,情境导入,返回,第2页,跳交谊舞人数应该是,2,倍数，如,12,、,14,跳圆圈舞人数应该是,5,倍数，如,15,、,20,交谊舞和圆圈舞演出能够分别选派多少人参加？,探究新知,返回,第3页,叠罗汉人数应该是,3,倍数，如,15,、,18,叠罗汉演出能够选派多少人参加？,返回,第4页,这些数有什么特征呢？,能够先用,50,以内数来研究。,返回,第5页,1,2,3,4,5,6,7,8,9,10,11,12,13,14,15,16,17,18,19,20,21,22,23,24,25,26,27,28,29,30,31,32,33,34,35,36,37,38,39,40,41,42,43,44,45,46,47,48,49,50,1,2,3,4,5,6,7,8,9,10,11,12,13,14,15,16,17,18,19,20,21,22,23,24,25,26,27,28,29,30,31,32,33,34,35,36,37,38,39,40,41,42,43,44,45,46,47,48,49,50,1,2,3,4,5,6,7,8,9,10,11,12,13,14,15,16,17,18,19,20,21,22,23,24,25,26,27,28,29,30,31,32,33,34,35,36,37,38,39,40,41,42,43,44,45,46,47,48,49,50,1,2,3,4,5,6,7,8,9,10,11,12,13,14,15,16,17,18,19,20,21,22,23,24,25,26,27,28,29,30,31,32,33,34,35,36,37,38,39,40,41,42,43,44,45,46,47,48,49,50,1,2,3,4,5,6,7,8,9,10,11,12,13,14,15,16,17,18,19,20,21,22,23,24,25,26,27,28,29,30,31,32,33,34,35,36,37,38,39,40,41,42,43,44,45,46,47,48,49,50,1,2,3,4,5,6,7,8,9,10,11,12,13,14,15,16,17,18,19,20,21,22,23,24,25,26,27,28,29,30,31,32,33,34,35,36,37,38,39,40,41,42,43,44,45,46,47,48,49,50,1,2,3,4,5,6,7,8,9,10,11,12,13,14,15,16,17,18,19,20,21,22,23,24,25,26,27,28,29,30,31,32,33,34,35,36,37,38,39,40,41,42,43,44,45,46,47,48,49,50,1,2,3,4,5,6,7,8,9,10,11,12,13,14,15,16,17,18,19,20,21,22,23,24,25,26,27,28,29,30,31,32,33,34,35,36,37,38,39,40,41,42,43,44,45,46,47,48,49,50,1,2,3,4,5,6,7,8,9,10,11,12,13,14,15,16,17,18,19,20,21,22,23,24,25,26,27,28,29,30,31,32,33,34,35,36,37,38,39,40,41,42,43,44,45,46,47,48,49,50,1,2,3,4,5,6,7,8,9,10,11,12,13,14,15,16,17,18,19,20,21,22,23,24,25,26,27,28,29,30,31,32,33,34,35,36,37,38,39,40,41,42,43,44,45,46,47,48,49,50,1,2,3,4,5,6,7,8,9,10,11,12,13,14,15,16,17,18,19,20,21,22,23,24,25,26,27,28,29,30,31,32,33,34,35,36,37,38,39,40,41,42,43,44,45,46,47,48,49,50,1,2,3,4,5,6,7,8,9,10,11,12,13,14,15,16,17,18,19,20,21,22,23,24,25,26,27,28,29,30,31,32,33,34,35,36,37,38,39,40,41,42,43,44,45,46,47,48,49,50,把,2,倍数涂成黄色。,返回,第6页,把,5,倍数涂成红色。,我发觉,个位,上是,0,、,2,、,4,、,6,、,8,数都是,2,倍数。,我发觉,个位,上是,0,或,5,数都是,5,倍数。,1,2,3,4,5,6,7,8,9,10,11,12,13,14,15,16,17,18,19,20,21,22,23,24,25,26,27,28,29,30,31,32,33,34,35,36,37,38,39,40,41,42,43,44,45,46,47,48,49,50,1,2,3,4,5,6,7,8,9,10,11,12,13,14,15,16,17,18,19,20,21,22,23,24,25,26,27,28,29,30,31,32,33,34,35,36,37,38,39,40,41,42,43,44,45,46,47,48,49,50,1,2,3,4,5,6,7,8,9,10,11,12,13,14,15,16,17,18,19,20,21,22,23,24,25,26,27,28,29,30,31,32,33,34,35,36,37,38,39,40,41,42,43,44,45,46,47,48,49,50,1,2,3,4,5,6,7,8,9,10,11,12,13,14,15,16,17,18,19,20,21,22,23,24,25,26,27,28,29,30,31,32,33,34,35,36,37,38,39,40,41,42,43,44,45,46,47,48,49,50,1,2,3,4,5,6,7,8,9,10,11,12,13,14,15,16,17,18,19,20,21,22,23,24,25,26,27,28,29,30,31,32,33,34,35,36,37,38,39,40,41,42,43,44,45,46,47,48,49,50,1,2,3,4,5,6,7,8,9,10,11,12,13,14,15,16,17,18,19,20,21,22,23,24,25,26,27,28,29,30,31,32,33,34,35,36,37,38,39,40,41,42,43,44,45,46,47,48,49,50,1,2,3,4,5,6,7,8,9,10,11,12,13,14,15,16,17,18,19,20,21,22,23,24,25,26,27,28,29,30,31,32,33,34,35,36,37,38,39,40,41,42,43,44,45,46,47,48,49,50,1,2,3,4,5,6,7,8,9,10,11,12,13,14,15,16,17,18,19,20,21,22,23,24,25,26,27,28,29,30,31,32,33,34,35,36,37,38,39,40,41,42,43,44,45,46,47,48,49,50,1,2,3,4,5,6,7,8,9,10,11,12,13,14,15,16,17,18,19,20,21,22,23,24,25,26,27,28,29,30,31,32,33,34,35,36,37,38,39,40,41,42,43,44,45,46,47,48,49,50,1,2,3,4,5,6,7,8,9,10,11,12,13,14,15,16,17,18,19,20,21,22,23,24,25,26,27,28,29,30,31,32,33,34,35,36,37,38,39,40,41,42,43,44,45,46,47,48,49,50,1,2,3,4,5,6,7,8,9,10,11,12,13,14,15,16,17,18,19,20,21,22,23,24,25,26,27,28,29,30,31,32,33,34,35,36,37,38,39,40,41,42,43,44,45,46,47,48,49,50,1,2,3,4,5,6,7,8,9,10,11,12,13,14,15,16,17,18,19,20,21,22,23,24,25,26,27,28,29,30,31,32,33,34,35,36,37,38,39,40,41,42,43,44,45,46,47,48,49,50,返回,第7页,我发觉,个位,上是,0,数既是,2,倍数，又是,5,倍数。,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,返回,第8页,1,2,3,4,5,6,7,8,9,10,2,10,4,6,2,8,12,14,16,18,20,2,倍数都是,偶数,。反之,返回,第9页,1,2,3,4,5,6,7,8,9,10,2,10,4,6,2,8,12,14,16,18,20,1,3,5,7,9,不是,2,倍数,它们都是,奇数,。,返回,第10页,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,个位上数没有什么规律。,找几个,3,倍数用计数器表示出来，看看各用了几个珠子，你有什么发觉？,3,倍数有什么特征呢？,返回,第11页,百,十,个,百,十,个,百,十,个,我发觉所用珠子个数都是,3,倍数。,15,21,39,6,是,3,倍数。,3,是,3,倍数。,12,是,3,倍数。,返回,第12页,百,十,个,百,十,个,百,十,个,15,21,39,6,是,3,倍数。,3,是,3,倍数。,12,是,3,倍数。,一个数所用,珠子个数和,，就是这个数,各个数位上数和,。,1+5=6,2+1=3,3+9=12,返回,第13页,百,十,个,百,十,个,百,十,个,15,21,39,6,是,3,倍数。,3,是,3,倍数。,12,是,3,倍数。,各个数位上数,和是,3,倍,数,，这个数就是,3,倍数吗？,1+5=6,2+1=3,3+9=12,返回,第14页,百,十,个,百,十,个,百,十,个,15,21,39,6,是,3,倍数。,3,是,3,倍数。,12,是,3,倍数。,1+5=6,2+1=3,3+9=12,我再找几个,3,倍数验证一下,返回,第15页,18，24，48,都是,3,倍数，它们各位数字和是,3,倍数吗？,18,24,48,1+8=9,4+8=12,9,是,3,倍数。,2+4=6,6,是,3,倍数。,12,是,3,倍数。,返回,第16页,一个数,各个数位,上数,和,是,3,倍数，这个数就是,3,倍数。,返回,第17页,1.,按要求填一填。,1,21,30,35,39,2,40,12,15,60,18,72,85,90,2,倍数,5,倍数,哪些数既是,2,倍数又是,5,倍数？,30,30,35,2,40,40,12,15,60,60,18,72,85,90,90,课堂练习,返回,第18页,2.,把下面数按要求分别填入对应圈内。,37,18,10,21,33,50,83,1,74,29,77,91,46,偶数,奇数,37,18,10,21,33,50,83,1,74,29,77,91,46,返回,第19页,3.,选出两张卡片，组成一个两位数，使这个两位数是,3,倍数，你认为该怎么选？,0,1,2,3,5,7,30,15,51,27,72,返回,第20页,进口,出口,怎样才能走出迷宫,?,只能经过,2,或,5,倍数。,4.,走迷宫。,返回,第21页,5.,任选两个数字组成符合下面要求数。,(1),奇数,:_,。,(2)2,倍数,:_,。,(3)3,倍数,:_,。,(4)5,倍数,:_,。,(5),既是,2,倍数又是,3,倍数,:_,。,(6),既是,3,倍数又是,5,倍数,:_,。,59,95,60,90,50,56,96,60,69,96,90,60,90,50,65,95,60,90,96,60,90,69,65,返回,第22页,这节课你们都学会了哪些知识？,课堂小结,2,、,3,、,4,1,、,个位上是,0,2,4,6,8,数,是,2,倍数。,4,、,凡是,2,倍数都是偶数。,不是,2,倍数都是奇数。,2,、,个位上是,0,5,数,是,5,倍数。,3,、一个数,各个数位,上数,和,是,3,倍数，这个数 就是,3,倍数。,返回,第23页,1.,从教材课后习题中选取；,2.,从课时练中选取。,课后作业,返回,第24页,