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,*,*,*,口算乘法,口算乘法,50,60,80,105,203,402,53,84,34,15,32,12,仔细观察这两组题目,,你们是怎样计算的?,复习导入,5060801052034025384,1605,3902,1504,800,780,600,143,136,243,42,78,72,243,再算:,43,12,60,12,72,先算:,203,60,1605,再算:,605,300,500,300,800,先算:,1005,500,探索新知,16053902150480078060014,你能提出什么数学问题?,探索新知,你能提出什么数学问题?探索新知,103,30,3,筐草莓有多少盒?,153,1,5,3,1,5,4,53,15,30,15,45,45,(盒),探索新知,103303筐草莓有多少盒?153 1 53154,153,45,想一想,:,1503,450,因为,153,45,,,所以,1503,450,。,1003,300,503,150,300,150,450,探索新知,15345 想一想:1503450因为153,610,60,2.,(,1,)橙子每盒,6,个,,10,盒有多少个?,69,54,54,6,60,所以,610,60,510,910,1810,4010,50,90,180,400,计算上面各题,你发现了什么?,我发现一个数乘,10,,积就在这个数的末尾添上,1,个,0,。,探索新知,61060 2.(1)橙子每盒6个,10盒有多少个?6,122,24,1220,2410,240,240,(,2,)苹果每盒,12,个,,20,盒有多少个?,探索新知,1222412202410240240(2)苹,还可以怎样计算呢?,想一想:,12020,2400,这道题你还会计算吗?,因为,1220,240,,,所以,12020,2400,。,1202,240,24010,2400,探索新知,还可以怎样计算呢?想一想:120202400这道题你还会,420,2000,88,90,78,960,860,690,4800,探索新知,42020008890789608606904800探索新知,432,86,86100,8600,因为,4320,860,,,所以,86010,8600,。,还可以怎样计算呢?,想一想:,43200,8600,这道题你还会计算吗?,探索新知,43286861008600因为4320860,,1.,做一做。,1404,156,1506,560,90,900,115,1105,144,55,550,56,234,2304,92,920,同学们,你都做对了吗?,探索新知,1.做一做。1404 15615065609,2.,填一填。,3,60,21,81,100,80,5,500,400,900,273,203,7,1805,5,探索新知,2.填一填。36021811008055004009002,3.,解决问题。,213,63,(人),(,1,),3,辆车最多可坐多少人,?,(,2,),80,人乘坐这,4,辆车,能坐下吗,?,214,84,(人),84,人,80,人,能坐下。,探索新知,3.解决问题。21363(人)(1)3辆车最多可坐多少,4,、一只虎体重,180,千克,一只熊的体重是虎的,2,倍。这只熊的体重是多少千克?,1802,360,(千克),答:这只熊的体重是,360,千克。,探索新知,4、一只虎体重180千克,一只熊的体重是虎的2倍。这只熊的体,75,260,820,88,900,440,80,210,390,51,480,720,5,、,探索新知,752608208890044080210390514807,1230,360,(个),(,1,),1,串糖葫芦,12,个山楂,,穿,30,串这样的糖葫芦需要,多少个山楂,?,(,2,),1,串糖葫芦卖,3,元,,30,串能卖多少钱,?,330,90,(元),6,、,探索新知,1230360(个)(1)1串糖葫芦12个山楂,(2)1,7,、,1150,550,(千克),答:李红家的蚕子可产茧,550,千克。,1180,880,(千克),答:李家村可产茧,880,千克。,1850,900,(元),答:,50,千克能卖,900,元钱。,探索新知,7、1150 550(千克)答:李红家的蚕子可产茧550,31030,1420,14200,9300,280,2800,1230,12030,3130,360,3600,930,3020,30200,600,6000,同学们,你都做对了吗?,探索新知,31030 14201420093002802,1.,把得数相同的算式用线连起来。,253,4220,2403,3040,3620,2450,155,2830,学以致用,1.把得数相同的算式用线连起来。2534220240,2.,解决问题。,1230,360,(个),(,1,)穿,1,串糖葫芦,12,个山楂,穿,30,串这样的糖葫芦需要多少个山楂,?,(,2,),1,串糖葫芦卖,3,元,,30,串能卖多少钱,?,330,90,(元),学以致用,2.解决问题。1230360(个)(1)穿1串糖葫芦1,880,20,60,76,90,660,100,800,学以致用,88020607690660100800学以致用,(,1,)鲸一分钟能游多少米?,(,2,)羚羊,40,秒能跑多少米?,(,3,)一只豹子在追赶奔跑中的羚羊,当距离羚羊,150,米的时,再过,20,秒能追上吗?,1160,660,(米),答:鲸一分钟能游,660,米。,2240,880,(米),答:羚羊,40,秒能跑,880,米。,(,31,22,),20,180,(米),180,150,答:再过,20,秒能追上羚羊。,学以致用,(1)鲸一分钟能游多少米?1160 660(米)答:鲸一,6050,3000,(克),答:,1,小时滴水,3,千克。,3000,克,3,千克,324,72,(千克),答:,1,天滴水,72,千克。,学以致用,6050 3000(克)答:1小时滴水3千克。3000克,(,1,)买学生票花了多少钱?,(,2,)你能提出一个数学问题并解答吗?,4012,480,(元),答:买学生票花了,480,元钱。,学以致用,(1)买学生票花了多少钱?4012 480(元)答:买学,
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