小数点的移动和单位换算.ppt

,小数移动与单位换算,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,例1:把0.07分别扩大到原来的10倍、100倍、1000倍，各是多少？,0.0710,0.7,7,70,【一题导解】,0.07100,0.071000,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,例2：把3.2分别缩小到原来的 ，各是多少？,0.32,0.032,0.0032,【一题导解】,1米=100厘米 100+45=145厘米,95,状元成才路,状元成才路,3、填一填,0.95米（ ）厘米,0.95100=95厘米,3千克=( )吨,31000=0.003吨,1米45厘米（ ）厘米,进率 低级单位 高级单位 进率,0.003,145,【一题导解】,【一题导学】, （ 扩大到倍 ）, （ 缩小到几份之一 ）,小数点，本领大，走一走，数变化。右走扩大用乘法，左走缩小用除法。移动缺位也不怕，快用“0”来补足它。,口诀：,一想：（ 单位间的进率是多少 ）,二看：（ 大化小还是小化大 ）,三算：（ 大化小乘以进率，小数点右移；小化大除以进率，小数点左移 ）,单位换算方法：,【一题导学】,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,0,2 9 6,例1：在括号里填上合适的数。,2.96,10,( ),100,( ),1000,( 296 ),2 9 6,.,29.6,2 9 6,.,0,0.296,小数点向右移动 位,小数点向左移动 位,小数点向右移动 位,一,两,三,.,【一题导学】,例2：我最棒，直接填得数。 2.8710= 3.91000 = 34.8110 = 21000 = 0.6710010 = 12.5100 1000=,0.002,3900,3.481,28.7,0.067,1.25,【一题导学】,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,例3：乐乐饰品店购进10个海宝玩具共花了45.5元，如果再购进1000个这样的玩具，需要多少钱？,答：需要45500元。,45.5 X （100010）= 45500（元）,45.5 10 X 1000 = 45500（元）,【一题导练】,300,86,进率 低级单位 高级单位 进率,例4：做一做，并说说改写方法。,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,状元成才路,6.32,8.035,0.43,5.6,0.3kg( )g 0.86m2( )dm2 6320米=( )千米 8035千克=( )吨 4角3分=( )元 5米6分米=( )米,【一题导练】,例5：判断。(对的打“”，错的打“”),(2)把千克数改写成吨数，要除以1000。( ),(3)因为580克=0.58千克，所以6千克580克就等于60.58千克。( ),(1)教室面积是56.8平方分米。( ),【一题导练】,例：小明买东西付了50元钱，营业员将商品价格的小数 点看错了一位，找给顾客45.75元，顾客说钱找多了，这 件商品正确的标价是多少？,50-45.75=4.25（元）,4.2510=42.5（元）,答：这件商品正确的标价是42.5元。,【一题导练】,例：把一个数的小数点先向左移动两位，再向右 移动三位，结果得0.6，那么原数是多少？,0.61001000=0.06,答：原数是6。,【一题导练】,例：甲数是乙数的100倍，若把乙数的小数点向左移动 一位后是56.01，则甲数是多少？,56.0110100=56010,答：甲数是