8.11%作为小数

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  作为小数

  

  [Figure 1]

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  The school is fundraising for a new gym. An amusement park owner has agreed to have a fundraiser at his park. He plans to donate 15% of every dollar spent at the park to the gym fund. How much of every dollar will be donated to the school? Write the  amount  as a decimal.
  ::学校是为新体育馆筹款的。 一个游乐公园业主已经同意在其公园举办一个筹款活动。 他计划将公园每花一美元15%的金额捐给体育馆基金。 每1美元中有多少将捐给学校? 将金额写为小数。

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  In this concept, you will learn how to write percents as decimals.
  ::在这个概念中,你会学习如何以小数点来写百分数。

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  Writing Percents as Decimals
  ::将百分比写入十进制

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  Percents and decimals are parts of a whole. A  percentage  is a quantity out of 100. A decimal number with two decimal digits also represents a quantity out of 100.
  ::百分数和小数数是整体的一部分。百分数是100中的一部分。百分数是100中的一部分。小数数加上两位小数数也是100中的一部分。

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  Compare 34% and 0.34.
  ::比较34%和0.34。

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  34% is 34 out of 100.The decimal 0.34 is 34 hundredths or 34 out of 100. Both quantities represent the same ratio.
  ::34%是100人中的34人。 小数点0.34是3400人,即100人中的34人。 两者的比例相同。

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  A percents can be written as a decimal by replacing “out of 100” with “hundredths.” Remove the percent symbol and move the  decimal point  two places to the left.
  ::以“ 百分百” 取代“ 百分数 ” , 就可以以小数表示一个百分比。 删除百分数符号,将小数点点 2 位移到左边。

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  Here is a percent:
  ::这是百分之一:

  $$\begin{array}{r}45\mathrm{\%}.\end{array}$$

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  Write 45% as a decimal.
  ::小数点后写45%。

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  First, remove the percent symbol.
  ::首先,去掉百分数符号

  $$\begin{array}{r}45\end{array}$$

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  Then, move the decimal point two places to the left. Remember that the decimal point is located between the ones and the tenths place.
  ::然后,将小数点 2 移到左边。记住小数点位于小数点和十点之间。

  $$\begin{array}{r}0.45\end{array}$$

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  45% is written as 0.45.
  ::45%的写法为0.45。

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  Let’s look at another percent.
  ::让我们再看看另一百分比。

  $$\begin{array}{r}5\mathrm{\%}\end{array}$$

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  Write 5% as a decimal.
  ::小数点后写5%。

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  First, remove the percent symbol.
  ::首先,去掉百分数符号

  $$\begin{array}{r}5\end{array}$$

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  Then, move the decimal point in two places to the left. There is no number to the left of 5. Use  zero  as a place holder.
  ::然后,将小数点移到左边两个位子。5点左侧没有数字。5点左侧没有数字。作为占位符使用零。

  $$\begin{array}{r}0.05\end{array}$$

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  5% is written as 0 .05
  ::5%的写作为 0.05

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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 the school fundraiser at the amusement park.
  ::早些时候,你在游乐园的 学校募捐会上遇到一个问题

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  15% of every dollar will be donated towards the school. Convert the percent to a decimal to find how much  per  dollar will be donated.
  ::每1美元15 % 将捐给学校。 将百分比转换为小数, 以找到每美元捐出多少钱 。

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  Write 15% as a decimal.
  ::小数点后写15%。

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  First, remove the percent symbol.
  ::首先,去掉百分数符号

  $$\begin{array}{r}15\end{array}$$

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  Next, move the decimal point two places to the left.
  ::下一步,将小数点 2 位移到左边。

  $$\begin{array}{r}0.15\end{array}$$

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  0.15 of every dollar will be donated to the school. Then, multiply $1 by 0.15.
  ::每一美元0.15美元将捐给学校,然后乘以1乘0.15

  $$\begin{array}{r}\mathrm{\$}1\times 0.15=\mathrm{\$}0.15\end{array}$$

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  $0.15 or 15 cents of every dollar will go to the school.
  ::每1美元15美分或15美分 将去学校。

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  Example 2
  ::例2

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  Write 15% as a decimal.
  ::小数点后写15%。

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  First, remove the percent symbol.
  ::首先,去掉百分数符号

  $$\begin{array}{r}15\end{array}$$

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  Then, move the decimal point two places to the left.
  ::然后,将小数点两点移到左边。

  $$\begin{array}{r}0.15\end{array}$$

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  15% is written as 0 .15
  ::15%写为0.15

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  Write the following percents as a decimal.
  ::将以下百分比写为小数点。

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  Example 3
  ::例3

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  Write 17% as a decimal.
  ::小数点后写17%。

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  First, remove the percent symbol.
  ::首先,去掉百分数符号

  $$\begin{array}{r}17\end{array}$$

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  Then, move the decimal point in two places to the left.
  ::然后,将小数点移到左边两个地方。

  $$\begin{array}{r}0.17\end{array}$$

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  17% is written as 0.17.
  ::17%的写法是0.17。

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  Example 4
  ::例4

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  Write 25% as a decimal.
  ::小数点后写25%。

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  First, remove the percent symbol.
  ::首先,去掉百分数符号

  $$\begin{array}{r}5\end{array}$$

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  Then, move the decimal point in two places to the left.
  ::然后,将小数点移到左边两个地方。

  $$\begin{array}{r}0.25\end{array}$$

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  25% is written as 0.25.
  ::25%的写法是0.25。

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  Example 5
  ::例5

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  Write 75% as a decimal.
  ::小数点后写75%。

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  First, remove the percent symbol.
  ::首先,去掉百分数符号

  $$\begin{array}{r}75\end{array}$$

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  Then, move the decimal point in two places to the left.
  ::然后,将小数点移到左边两个地方。

  $$\begin{array}{r}0.75\end{array}$$

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  75% is written as 0.75.
  
  ::75%的写法是0.75。

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  Review
  ::回顾

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  Write each percent as a decimal.
  ::每一百分率写为小数点。

  1. 54%
  2. 11%
  3. 6%
  4. 12%
  5. 89%
  6. 83%
  7. 19%
  8. 4%
  9. 9%
  10. 32%
  11. 65%
  12. 88%
  13. 78%
  14. 67.5%
  15. 18.2%

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  Review (Answers) 
  ::回顾(答复)

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  Click   to see the answer key or go to the Table of Contents and click on the Answer Key under the 'Other Versions' option.
  ::单击可查看答题键, 或转到目录中, 单击“ 其他版本” 选项下的答题键 。

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  Resources
  ::资源