8.15小数表示百分比

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• 选择节小数表示百分比

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  小数表示百分比

  

  [Figure 1]

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  Lisa works at a spice factory. She’s writing a description of their new barbeque spice blend for their catalogue. Every pound of the new barbeque blend contains 0.1 more pounds of paprika than the old blend. Lisa wants to describe the increase as a percent. What is the percent increase of paprika in the new recipe?
  ::Lisa在一家香料工厂工作。她正在为目录写关于他们新的烧烤香料混合物的描述。 新的烤肉混合中每磅含有比旧混合中多0.1磅的辣椒。 Lisa想将增加量描述为%。 新配方中辣椒的增长率是多少?

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  In this concept, you will learn how to convert decimals to percents.
  ::在这个概念中,你会学习如何将小数点转换为百分比。

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  Writing Decimals as Percents
  ::将十进制数写入百分比

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  In  order  to write a percent as a decimal, remove the percent sign and move the  decimal point  two places into the left. These two places represent the hundredths place of the decimal.
  ::为了将百分比写为小数点,删除百分点符号并将小数点 2 位移到左边。这两个位数代表小数点位数的第100位数。

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  31% is written as 0.31.
  ::31%为0.31。

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  Decimals can also be written asa percent by doing the reverse. Move the decimal point two places to the right because two decimal places represent hundredths and percents are out of 100. Then, add a percent sign.
  ::十进制也可以通过反转写为百分比。 将小数点 2 移到右边, 因为两小数点代表百分百, 百分数代表100。 然后, 添加一个百分点符号 。

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  Write 0.14 as a percent.
  ::0.14 以百分比写为0.14。

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  First, move the decimal point two places to the right. Then, add the percent sign.
  ::首先,将小数点两点移到右边。然后,添加百分数符号。

  $$\begin{array}{r}0.14=14\mathrm{\%}\end{array}$$

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  0.14 is written as 14%.
  ::0.14的写法为14%。

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  For a decimal number with a  zero  in the tenths place, move the decimal point two places to the right and write the percent without the zero. Remember, the zero is only a place holder.
  ::对于十进制为零的十进制数字,将小数点二位移到右边,并将百分比写成零。记住,零只是一个占位符。

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  Write .03 as a percent.
  ::将0.03写成百分比

  $$\begin{array}{r}0.03=3\mathrm{\%}\end{array}$$

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  0.03 is written as 3%.
  ::003是3%的写法。

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  For a single digit decimal number, move the decimal point two places to the right and put a zero in the ones place.
  ::对于一位数的十进制数字,将小数点 2 位移到右侧,并将一个位数的位数为零。

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  Write .2 as a percent.
  ::将 2 写成百分比 。

  $$\begin{array}{r}0.20=20\mathrm{\%}\end{array}$$

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  0.2 is written as 20%.
  ::0.2%为20%。

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  If you have a number with more than two decimal digits, repeat the same process, but you will have a percent that is also a decimal.
  ::如果数字小数位数超过两位位数,请重复同样的进程,但您将有一个百分比,也就是小数位数。

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  Write 0.345 as a percent.
  ::0.345 写成百分比为0.345。

  $$\begin{array}{r}0.345=34.5\mathrm{\%}\end{array}$$

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  0.345 is written as 34.5%.
  ::0.345 写为34.5%。

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  Examples
  ::实例

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  Example 1
  ::例1

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  Earlier, you were given a problem about Lisa at the spice factory.
  ::早些时候,你在香料厂 遇到莉莎的问题

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  She wants to describe the increase of 0.1 pounds of paprika in the new barbeque recipe. To do so, she must convert 0.1 to a percent.
  ::她想描述在新的烧烤配方中增加0.1磅的辣椒。要做到这一点,她必须把0.1%转换为1%。

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  First, she must move the decimal point two places to the right and put a zero in the ones place. Then, she adds a percent sign.
  ::首先,她必须把小数点两点移到右边,然后在那个地方放一个零。然后,她增加了一个百分位符号。

  $$\begin{array}{r}0.10=10\mathrm{\%}\end{array}$$

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  She can describe the new barbecue recipe as having 10% more paprika than the old recipe.
  ::她可以形容新的烧烤食谱 比旧食谱多吃10%的辣椒

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  Example 2
  ::例2

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  Write the decimal as a percent.
  ::将小数点写成百分比。

  $$\begin{array}{r}0.009\end{array}$$

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  First, move the decimal point two places to the right and add a percent sign.
  ::首先,将小数点两点移到右边,并添加一个百分数符号。

  $$\begin{array}{r}0.009=0.9\mathrm{\%}\end{array}$$

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  0.009 is written as 0.9%.
  ::009的写法是0.9%。

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  Example 3
  ::例3

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  Write the decimal as a percent.
  ::将小数点写成百分比。

  $$\begin{array}{r}0.85\end{array}$$

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  Move the decimal point two places to the right and add a percent sign.
  ::将小数点 2 位移到右边,并添加一个百分比符号。

  $$\begin{array}{r}0.85=85\mathrm{\%}\end{array}$$

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  0.85 is written as 85%.
  ::0.85 写为85%。

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  Example 4
  ::例4

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  Write the decimal as a percent.
  ::将小数点写成百分比。

  $$\begin{array}{r}0.09\end{array}$$

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  Move the decimal point two places to the right and add a percent sign.
  ::将小数点 2 位移到右边,并添加一个百分比符号。

  $$\begin{array}{r}0.09=9\mathrm{\%}\end{array}$$

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  0.09 is written as 9%.
  ::0.09 书写为9%。

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  Example 5
  ::例5

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  Write the decimal as a percent.
  ::将小数点写成百分比。

  $$\begin{array}{r}0.5\end{array}$$

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  Move the decimal point two places to the right and put a zero in the ones place.
  ::将小数点 2 位移到右边,并在这些位子中加上零。

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  Then, add a percent sign.
  ::然后,加一个百分数符号。

  $$\begin{array}{r}0.50=50\mathrm{\%}\end{array}$$

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  0.5 is written as 50%.
  ::0.5的写法为50%。

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  Review
  ::回顾

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  Write the following decimal numbers as a percent.
  ::将以下小数数写为百分比。

  1. 0.31
  2. 0.56
  3. 0.43
  4. 0.08
  5. 0.01
  6. 0.4
  7. 0.6
  8. 0.65
  9. 0.33
  10. 0.19
  11. 0.3
  12. 0.9
  13. 0.11
  14. 0.18
  15. 0.34
  16. 0.99
  17. 0.21
  18. 0.88

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  Review (Answers) 
  ::回顾(答复)