1、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,*,北师,大版,数学 五年级 上册,练习四(,1,),复习旧知,课堂小结,课后作业,倍数与因数,巩固练习,3,第1页,复习旧知,1.,请,划去以下不是,60,因数数。,1,15,20,16,6,18,3,4,2,60,120,30,5,12,第2页,2,4,6,8,10,12,14,16,18,20,尾数是,2,,,4,,,6,,,8,,,0,2.,我会填。,(,1,)请写出小于,20,2,倍数,:,2,倍数特征是:,第3页,3,6,9,12,15,18,21,24,27,30,各个数位上数加起来和是,3,倍数
2、2.,我会填。,(,2,)请写出小于,30,3,倍数,:,3,倍数特征是:,第4页,(,3,)请,写出小于,30,5,倍数,:,5,,,10,,,15,,,20,,,25,,,30,尾数是,0,或,5,。,2.,我会填。,5,倍数特征是:,第5页,巩固练习,2,4,12,6,3,24,1.,组,内同学按要求交换角色完成。从下面数中选出三个数,组成乘法或除法算式,再说说哪个数是哪个数倍数,哪个数是哪个数因数。,第6页,巩固练习,2,4,12,6,3,24,2,3,6,2,6,12,3,4,12,2,12,24,6,是,2,和,3,倍,数,2,和,3,是,6,因,数,12,是,2,和,6,倍,
3、数,2,和,6,是,12,因,数,12,是,4,和,3,倍,数,4,和,3,是,12,因,数,24,是,2,和,12,倍,数,2,和,12,是,24,因,数,第7页,2.,用,24,个小正方形摆长方形,有几个摆法?填一填,想一想,,24,因数有哪些?,长,宽,24,1,12,2,8,3,6,4,24,因数有,1,,,2,,,3,,,4,,,6,,,8,,,12,,,24,。,第8页,3.,想,一想,填一填。,60,72,48,35,95,73,84,93,99,5,倍数,2,倍数,3,倍数,60,95,35,60,72,48,84,60,72,48,84,93,99,第9页,4.,一,个数既是
4、6,倍数,,又是,24,因数,,这个数可能是多少?,大于或等于,6,。,小于或等于,24,。,小于或等于,24,6,倍数:,12,,,24,大于或等于,6,24,因数:,8,,,12,,,24,答:这个数可能是,12,或,24,。,第10页,5.,分,一分,填一填。并与同伴交流你想法。,奇数,偶数,质数,合数,1,10,12,37,25,54,417,102,298,23,1,25,37,417,23,10,12,54,102,298,37,23,10,12,25,54,102,417,298,第11页,我和另一个数都是,质数,,我们,和是,15,。,我是一个,偶数,,也是一个两位数,十位数
5、字与个位数字,积是,18,。,6.,猜,猜我是谁。,请与同桌合作,一起做“猜猜我是谁”数学活动。,我是,5,。,我们是,2,和,13,。,我们是,92,和,36,。,我是比,3,大,比,7,小,奇数,。,第12页,7.,找,出,27,全部因数和,100,以内,7,全部倍数。,27,全部因数:,100,以内,7,全部倍数:,27,1,27,3,9,1,3,,,9,,,27,7,,,14,,,21,,,28,,,35,,,42,,,49,,,56,,,63,,,70,,,77,,,84,,,91,,,98,第13页,8.,选哪种包装盒能恰好把,90,饮料装完?,6,瓶,6,瓶地装。,5,瓶,5,瓶
6、地装。,3,瓶,3,瓶地装。,8,瓶,8,瓶地装。,90,因数有:,1,,,2,,,3,,,5,,,6,,,9,,,10,,,15,,,18,,,30,,,45,,,90,还有其它包装方式吗?,只要盒子里瓶数是,90,因数就行。,第14页,这节课你们都学会了哪些知识?,乘,数,乘数积,课堂小结,被,除数,除数商,因数,因数,倍数,因数,因数,倍数,第15页,这节课你们都学会了哪些知识?,2,倍数特征是,尾数是,2,,,4,,,6,,,8,,,0,。,5,倍数特征是,尾数是,0,或,5,。,3,倍数特征是,各数位上数字之和是,3,倍数,。,第16页,这节课你们都学会了哪些知识?,因数只有,1,和它本身数是,质数,。除了,1,和它本身之外还有别因数数是,合数,。,第17页,这节课你们都学会了哪些知识?,自然数,奇数(不是,2,倍数),偶数(,2,倍数),0,自然数,质数,合数,0,1,第18页,1.,从教材课后习题中选取;,2.,从课时练中选取。,课后作业,第19页,