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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,*,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,*,公倍数和最小公倍数,金银滩复兴学校 石学凤,义务教育课程标准实验教科书五年级下册数学,4的,倍数:,6的倍数:,23,1,0,2,3,4,5,6,7,8,9,10,11,12,13,14,15,16,17,18,19,20,21,22,24,23,1,0,2,3,4,5,6,7,8,9,10,11,12,13,14,15,16,17,18,19,20,21,22,24,4,,8,,12,,16,,20,,24,6,,12,,18,,24,4的,倍数:,6的倍数:,23,1,0,2,3,4,5,6,7,8,9,10,11,12,13,14,15,16,17,18,19,20,21,22,24,23,1,0,2,3,4,5,6,7,8,9,10,11,12,13,14,15,16,17,18,19,20,21,22,24,4,,8,,12,,16,,20,,24,6,,12,,18,,24,12,12,12,24,24,,24,既是4的倍数,又是6的倍数。,12,24是4和6公有的倍数,叫做它们的 公倍数。,6,的倍数,4,的倍数,4,和,6,的倍数,4,,,8,,,16,,,20,,,6,,,12,,,18,,,12,,,24,,,12,12,是,4,和,6,的最小公倍数,3,2,6,4,6,9,8,10,12,12,6,6,12,12,铺一铺,要求:边操作边思考(1)拼成的正方形的边长是多少?(2)与长方形墙砖的长和宽又什么关系?,这种墙砖长3分米,宽2分米。,如果用这种墙砖铺一个正方形(用的墙砖都是整块),正方形边长可以是多少分米?最小是多少分米?,23,1,0,2,3,4,5,6,7,8,9,10,11,12,13,14,15,16,17,18,19,20,21,22,24,画一画,说一说,小松鼠一次跳2格,小猴一次能跳3格,它们从同一点往前跳,跳到第几格时第一次跳到同一点,第二次跳到同一点是第几格?第三次呢?,6,12,18,8,的倍数,6,的倍数,4,和,6,的倍数,6,,,12,,,18,,,24,,,30,,,36,,,42,,,48,8,,,16,,,24,,,32,,,40,,,48,24,,,48,1,、把,6,和,8,的,倍数和公倍数不超过,50,的填在下面的圈中,在找出他们的最小公倍数。,6,的倍数,8,的倍数,6,,,12,,,18,,,30,,,36,,,42,8,,,16,,,32,,,40,填一填,3,的,倍数有:,5,的倍数有:,3,和,5,的公倍数有:,3,和,5,的最小公倍数有:,3,,,6,,,9,,,12,,,15,,,18,,,21,,,24,,,27,,,30,,,33,,,5,,,10,,,15,,,20,,,25,,,30,,,35,,,,,30,,,15,15,15,30,30,15,练一练,暑假期间,小林和小军都去参加游泳训练,小林每隔4天去一次,小军每隔5天去一次。7月31日两人同时参加了游泳训练后,几月几日他们又再次相遇。,再见!,
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