Course: 5.2 以十进制书写百分比

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以十进制写入百分比
Mina works at a poultry processing plant that also cooks chicken. One pound of chicken cooked without the skin contains about 0.07 pounds of fat. How can Mina assess what percent of cooked chicken is fat and what percent is not?
::Mina在一家家禽加工厂工作,该厂也做鸡。一磅没有皮肤煮熟的鸡肉含有大约0.07磅的脂肪。米纳如何评估煮熟的鸡肉中有多少是脂肪,什么不是?

In this concept, you will learn to write percent as decimals.
::在此概念中,您将学会以小数位数来写百分比。

Percents as Decimals
::百分数作为十进数

A percent is a part of a whole. It is a ratio compared to 100. Fractions and decimals are parts of a whole too. Since this is true, you can interchange the form that you write these quantities in. You can write a fraction as a decimal and as a percent. You can also write a percent as a decimal or a decimal as a percent and you can do the same with the fractions too.
::A% 是整体的一部分。这是与 100 比较的比率。小数和小数也是整体的一部分。由于这是事实, 您可以将您写入这些数量的形式替换为整体。您可以以小数和百分比的形式写入一个小数。您也可以以小数和百分比的形式写入一个小数。您也可以以小数或小数以百分比的形式写入一个百分数。您也可以以小数或小数以百分比的方式写入一个百分数。

Let’s start by writing percent as decimals and decimals as percent. Decimal places represent powers of ten . The second decimal place is the hundredths place. The decimal 0.18 means eighteen-hundredths.
::让我们先以小数点和小数点的百分数来写百分比。十进制位数代表十的功率。小数点的第二位数是一百位数。小数点为十进制0.18表示八百位数。

Let’s look at an example.
::让我们举个例子。

Write 56% as a decimal.
::小数点后写56%。

First, you know that the % sign means “out of 100” or that the denominator of the fraction formed from the decimal is 100. You can say that decimal places represent tens and hundreds too. Two decimal places represents hundreds, just like the percent sign, %, represents hundreds.
::首先,您知道 % 符号表示“ 超过 100 ” , 或者小数点形成的分母分母为 100 。您可以说小数点也代表几十个和数百个。小数点表示数百个, 就像百分点表示的百分位表示的百个。

To change a percent to a decimal, you move the decimal point two places to the left and remove the percent sign.
::要将百分比修改为小数点后,将小数点两点移到左边,并删除百分数符号。

$\begin{aligned} 56 % = 0.56 \end{aligned}$
$\begin{align*}56\% = 0.56\end{align*}$

Let’s look at a few more examples
::让我们再举几个例子

Write 88% as a decimal.
::将88%的十进制写为十进制。

To change a percent to a decimal, you move the decimal point two places to the left and remove the percent sign.
::要将百分比修改为小数点后,将小数点两点移到左边,并删除百分数符号。

$\begin{aligned} 88 % = 0.88 \end{aligned}$
$\begin{align*}88\% = 0.88\end{align*}$

Write 125% as a decimal.
::880.88 将小数点的125%写为小数点。

To change a percent to a decimal, you move the decimal point two places to the left and remove the percent sign.
::要将百分比修改为小数点后,将小数点两点移到左边,并删除百分数符号。

$\begin{aligned} 125 % = 1.25 \end{aligned}$
$\begin{align*}125\% = 1.25\end{align*}$

You can work the other way around too and write decimals as percent. Here you will move the decimal point two places to the right and add a percent sign.
::您也可以在另一边工作, 并将小数点写成百分比。在这里您将把小数点 2 移到右边, 并添加一个百分比符号。

Let’s look at an example.
::让我们举个例子。

Write 0.45 as a percent.
::写0.45 百分比。

First, you move the decimal point two places to the right. and next add a percent sign.
::首先,将小数点 2 位移到右边。然后添加一个百分比符号。

$\begin{aligned} 0.45 = 45 \end{aligned}$
$\begin{align*}0.45 = 45\end{align*}$

Next, add a percent sign.
::下一步,加一个百分数符号。

$\begin{aligned} \begin{array}{rcl} 0.45 & = & 45 \\ = & 45 % \end{array} \end{aligned}$
$\begin{align*}\begin{array}{rcl} 0.45 &=& 45 \\ &=& 45\% \end{array}\end{align*}$

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

First, you move the decimal point two places to the right.
::首先,将小数点二移到右边。

$\begin{aligned} 0.345 = 34.5 \end{aligned}$
$\begin{align*}0.345 = 34.5\end{align*}$

Next, add a percent sign.
::下一步,加一个百分数符号。

$\begin{aligned} \begin{array}{rcl} 0.345 & = & 34.5 \\ = & 34.5 % \end{array} \end{aligned}$
$\begin{align*}\begin{array}{rcl} 0.345 &=& 34.5 \\ &=& 34.5\% \end{array}\end{align*}$

Examples
::实例

Example 1
::例1

Earlier, you were given a problem about Mina and her chickens.
::早些时候,你得到一个问题关于米娜和她的鸡。

Mina needs to figure out the percent of fat in one pound of cooked chicken given that 0.07 pounds is fat.
::米娜需要弄清楚一磅熟鸡的脂肪含量鉴于0.07磅是脂肪

First, convert this amount of fat to a percent. When converting a decimal to a percent, you move the decimal point two places to the right then add the percent sign.
::首先,将这个脂肪量转换为百分之一。当将小数点转换为百分之一时,将小数点点的两点移到右边,然后添加百分点符号。

$\begin{aligned} 0.07 = 7 % \end{aligned}$
$\begin{align*}0.07 = 7\%\end{align*}$

Next, answer the question “What percent is not fat?” The amount of fat and the amount that is not fat must add to give you 100%. So subtract the percentage of fat from 100.
::接下来,回答一个问题,“什么百分比不是脂肪?” 脂肪的含量和非脂肪的含量必须加上100%。所以从100中减去脂肪的百分比。

$\begin{aligned} 100 % - 7 % = 93 % \end{aligned}$
$\begin{align*}100\% - 7\% = 93\%\end{align*}$

The answer is 7% and 93%. The 7% represents the percent of fat in the cooked chicken. The 93% represents the percent of chick that is not fat.
::答案是7%和93%。7%是煮鸡中脂肪的百分率。93%是不胖的小鸡的百分率。

Example 2
::例2

Write 0.455 as a percent.
::写0.455 百分比。

First, when converting a decimal to a percent, you move the decimal point two places to the right. This represents the hundredths that are shown with a percent sign.
::首先,当将小数点转换为百分比时,将小数点点向右移两个位数。这表示以百分位符号显示的百位数。

$\begin{aligned} 0.455 = 45.5 \end{aligned}$
$\begin{align*}0.455 = 45.5\end{align*}$

Next, add a percent sign.
::下一步,加一个百分数符号。

$\begin{aligned} \begin{array}{rcl} 0.455 & = & 45.5 \\ = & 45.5 % \end{array} \end{aligned}$
$\begin{align*}\begin{array}{rcl} 0.455 &=& 45.5 \\ &=& 45.5\% \end{array}\end{align*}$

The answer is 45.5%.
::答案是45.5%。

Write each example as a decimal or a percent.
::将每个例子写成小数点或百分比。

Example 3
::例3

0.48

First, notice that this is in decimal form and thus you need to change it to a percent. When converting a decimal to a percent, you move the decimal point two places to the right. This represents the hundredths that are shown with a percent sign.
::首先,请注意这是小数数格式, 因此您需要将其修改为百分比。当将小数点转换为百分比时, 您会将小数点 2 位移到右边。这表示以百分位符号显示的百位数。

$\begin{aligned} 0.48 = 48 \end{aligned}$
$\begin{align*}0.48 = 48\end{align*}$

Next, add a percent sign.
::下一步,加一个百分数符号。

$\begin{aligned} 0.48 = 48 % \end{aligned}$
$\begin{align*}0.48 = 48\%\end{align*}$

The answer is 48%.
::答案是48%。

Example 4
::例4

57.5%

First, notice that this is in percent form and thus you need to change it to a decimal. When converting a percent to a decimal, you first remove the percent sign.
::首先,请注意这是百分比格式, 因此您需要将其修改为小数点。当将百分比转换为小数点时, 您首先删除百分比符号。

$\begin{aligned} 57.5 % = 57.5 \end{aligned}$
$\begin{align*}57.5\% = 57.5\end{align*}$

Next, move the decimal point two places to the left.

$\begin{aligned} 57.5 % = 0.575 \end{aligned}$
$\begin{align*}57.5\% = 0.575\end{align*}$

The answer is 0.575.
::答案是0.575

Example 5
::例5

0.18

First, notice that this is in decimal form and thus you need to change it to a percent. When converting a decimal to a percent, you move the decimal point two places to the right.
::首先,请注意这是小数点表单, 因此您需要将其修改为百分比。当将小数点转换为百分比时, 您会将小数点 2 位移到右边。

$\begin{aligned} 0.18 = 18 \end{aligned}$
$\begin{align*}0.18 = 18\end{align*}$

Next, add a percent sign.

$\begin{aligned} 0.18 = 18 % \end{aligned}$
$\begin{align*}0.18 = 18\%\end{align*}$

The answer is 18%.
::答案是18%。

Review
::回顾

Write the following percent values as decimals.
::将以下百分比值写为小数点。

1. 18%

2. 35.7%

3. 6.09%

4. 0.008%

5. 0.028%

6. 0.9%

7. 31.5%

8. 12.3%

Write the following decimals as a percent.
::将以下小数点写成百分比。

9. 0.52

10. 0.02

11. 1.17

12. 5

13. 0.09

14. 0.876

15. 0.3

16. 0.0001

Review (Answers)
::回顾(答复)

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。

Resources
::资源

Section outline

General

以十进制写入百分比

Percents as Decimals ::百分数作为十进数

Examples ::实例

Example 1 ::例1

Example 2 ::例2

Example 3 ::例3

Example 4 ::例4

Example 5 ::例5

Review ::回顾

Review (Answers) ::回顾(答复)

Resources ::资源

Percents as Decimals
::百分数作为十进数

Examples
::实例

Example 1
::例1

Example 2
::例2

Example 3
::例3

Example 4
::例4

Example 5
::例5

Review
::回顾

Review (Answers)
::回顾(答复)

Resources
::资源