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我们被要求将7/8转化成小数及百分数形式

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我们从小数开始，因为我们会发现

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从小数变到百分数非常容易

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现在，无论何时你看到一个像这样的问题

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它总有些让人困惑

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到底如何才能将它转化成一个小数，或是占100的

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一定比例，也就是百分比

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同时你要记住7除以8，或7/8，是

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完全等价的

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这表示实际上是7被8除

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不是7除8

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7被8除

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分子被分母除

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然后你说，我怎样才能把它变成小数

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实际上，我们只需要做一个长一点的除法问题，但我们

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会一直除下去直到小数点后一位，

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即没有余数，或找到循环小数

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你稍后就会会明白其中的意义的

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在这个问题上， 我们得不到任何循环小数

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因此，让我们尝试

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7被8除

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那么，7 是 8 的多少倍？

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好吧，7不是8的倍数

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或者说0倍

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实际上，让我们确定所有思路

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都保持清晰，让我们加上小数点

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你可以把它看成8是7.000的多少倍

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实际上你想加多少0就可以加多少，直到

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完成除法

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现在我们看到小数点在7之后

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就在上面

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所以我们说8是7的0倍

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0乘以8等于0

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你减去

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7减0等于7

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现在我们可以移下来一个零

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我们移下来一个零

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它变成了70

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然后你猜70是8的多少倍？

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8乘8得64，所以8有效

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8乘9得72

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9太大了

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所以70是8的8倍

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8乘8得64

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当你用70减64得6时

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你仍有一个余数，所以继续

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让我们移下另一个零

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现在你移下一个零到这里，所以你说

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60是8的多少倍

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这样就有小数点了8乘8是64，太大了

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8乘7是56，所以7成立

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所以60是8的7倍

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7乘8得56

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你减去

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60减56得4

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现在还是有余数，继续

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在后面加0

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让我们在这加一个零

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40是8的多少倍？

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8乘5是40，所以完美整除

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所以是5倍

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5乘8得40

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减去

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没有余数

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所以，对于小数，我们刚刚解决了7分之8

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等于7除以8，即0.875

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所以把7/8表示为小数为0.875

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现在我们完成了小数部分

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下一步就是百分比

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如果你有小数形式，把它转化成百分比

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非常容易

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只需要把小数点右移两位

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并加上百分号

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我认为这很好理解

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现在你问，它是100的多少倍

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你可以把它看作875分之1000

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让我把这个写下来

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你可以把它当作分数

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你可以说，这是875/1000

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我们曾经就是这么读的，这是

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千分之一位

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或者你可以把它看做87.5/100

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如果你只把小数点移两位，它是87.5/100

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或者你同时用10除分母

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和分子，你也可以得到

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这实际上就是100分之87.5，所以这第二种

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表达方式，实际上就是

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百分之87.5

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所以这就是87.5

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这就告诉你了为什么这个论证成立

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但更简单的方式，如果你有一个数的小数形式，转化

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成百分比，你只需要用100乘该小数

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然后加上百分号，实际就是

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表示除以100，所以你同时乘以

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和除以100

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所以你乘以这个数以100，也就是

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将小数点右移2为

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变成87.5，然后你

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把百分号加上

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也就是除以100

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所以你乘上100再除以100

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并没有改变这个数

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希望这讲的通

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另一个要记住的是，因为有时你可能

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困惑，我应该把小数点右移

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还是把小数点左移，是否小数形式的数

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总是小于百分比

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形式的数?

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不仅仅更小，而且

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刚好是100分之一

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小数形式刚好是

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87.5的一百分之一

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很显然，当你把百分号加上，这两个数变成

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刚好相等