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,*,的乘法口诀,2013-12,2013-11-25,1,把口诀说完整。,二八（）四六（）五八（）,六八（）三七（）三八（）,六七（）五七（）五六（）,2,口算。,88=46=75=68=,58=77=84=86=,问题：你们算得真快，说说怎么算得这么快呀。,过渡：这节课我们接着来学习有关,9,的乘法口诀。,复习,一条龙舟上有九个人，九条龙舟上一共有多少人？,请你来过关,27,36,45,54,63,72,81,1,个,9,2,个,9,3,个,9,4,个,9,5,个,9,6,个,9,7,个,9,8,个,9,9,个,9,19,9,91,9,19,9,91,9,29,18,92,18,19,9,91,9,29,18,92,18,39,27,93,27,19,9,91,9,29,18,92,18,39,27,93,27,49,36,94,36,19,9,91,9,29,18,92,18,39,27,93,27,49,36,94,36,59,45,95,45,19,9,91,9,29,18,92,18,39,27,93,27,49,36,94,36,59,45,95,45,69,54,96,54,19,9,91,9,29,18,92,18,39,27,93,27,49,36,94,36,59,45,95,45,69,54,96,54,79,63,97,63,19,9,91,9,29,18,92,18,39,27,93,27,49,36,94,36,59,45,95,45,69,54,96,54,79,63,97,63,89,72,98,72,19,9,91,9,29,18,92,18,39,27,93,27,49,36,94,36,59,45,95,45,69,54,96,54,79,63,97,63,89,72,89,72,99,81,19,9,29,18,39,27,49,36,59,45,69,54,79,63,89,72,99,81,一九得九,二,九十八,三九二十七,四九三十六,五九四十五,六九五十四,七九六十三,八九七十二,九九八十一,编九的口诀,91,9,92,18,93,27,94,36,95,45,96,54,97,63,98,72,一九得九,二,九十八,三九二十七,四九三十六,五九四十五,六九五十四,七九六十三,八九七十二,九九八十一,编九的口诀,1,9=,2 9 =,3 9=,7 9 =,4 9 =,5 9,=,6 9 =,8 9 =,18,9,27,36,45,54,63,72,9,的 乘 法口诀,9 9 =,81,归纳小结,1,、,9,的乘法口诀有,9,句。每相邻两句口诀的得数相差,9,。,2,、,9,的,1,倍比,10,少,1,，,9,的,2,倍比,20,少,9,的,9,倍,比,90,少,9,。也就是,9,和几相乘就等于几十减几的差。,3,、积的十位数字与个位数字的和都是,9,。,4,、,9,的乘法口诀的积，对应位置的积的个位和十位的数字相互交换了位置，比如，二九十八，九九八十一，,18,，,81,。,口算,(,并说出用的是哪句口诀,),95=,69=,94=,93=,92=,91=,99=,79=,98=,45,36,18,81,72,54,27,9,63,能帮助可爱的小动物找到它们的家吗,?,3,9,5,9,6,9,45,27,54,5,9,9,7,39,98,看口诀说出两个乘法算式,三九二十七,九九八十一,一九得九,七九六十三,1,9,9,9,1,9,7,9,63,9,7,63,3,9,27,9,3,27,9,9,81,4,9,36,7,9,63,5,9,45,2,9,18,看算式说口诀,七九六十三,五九四十五,四九三十六,二九十八,3,9,27,6,9,54,8,9,72,9,9,81,看算式说口诀,六九五十四,八九七十二,三九二十七,九九八十一,比比看：,你能写几道乘法算式，看谁写的多,12 24 18,2X6=12,6X2=12,3X4=12,4X3=12,4X6=24,6X4=24,3X8=24,8X3=24,3X6=18,6X3=18,2X9=18,9X2=18,来点高难度的！哈哈！,小华每天要写,9,个大字，她一个星期能写几个大字,？,1,、,超市里面一瓶红酒的价格是,9,元，王阿姨要买,5,瓶红酒需要多少元钱？,2,、,请同学们完成书上的练习！,写完要仔细检查哦！,