Section: 承认和写写百分比 | 5.1 承认和写作百分比

Section outline

Simon is the weather forecaster for his local radio station. Based on his data, he announces that tomorrow’s probability of precipitation is 70%. What does this mean?
::西蒙是当地电台的天气预报员。根据他的数据,他宣布明天的降水概率为70%。这是什么意思?

In this concept, you will learn to recognize and write percent.
::在这个概念中,你会学会承认和写写百分比。

Percents
::百分比

You see percentages almost every day. If you walk into a store of any kind, you will often see percent on a sign. Whether it is a sale sign for 10% off or a sign in a bank for a new mortgage rate , by looking all around you, you will see percent.
::几乎每天都能看到百分比。如果你走进任何类型的商店, 通常会在牌子上看到百分比。无论它是10%的减价销售信号, 还是银行的新按揭利率信号, 环顾四周, 你会看到百分比。

A percent is a part of a whole. It is a part of a whole that is being compared to 100. In this way, you can also think of a percent as a ratio. Remember that a ratio is a comparison between two quantities. Fractions and decimals are also parts of a whole. You can say that fractions, decimals and percent are all related.
::A% 是整体的一部分。它是一个整体的一部分, 正在与 100 进行比较。这样, 您也可以将%当作一个比例。记住, 比例是两个数量之间的比较。小数和小数也是整体的一部分。您可以说, 分数、小数和百分比都是相关的。

Consider the word “percent.” Its root “cent” means one hundred and “per” implies division or means “for each.” If you have three candies per person, it means three candies for each person. So “percent” means one for every one hundred.
::考虑一下“百分比”一词。其根“百分比”意味着一百零一“百分之一”意味着分裂或“对每人”的意思。如果每人有三只糖果,那么这意味着每人三只糖果。因此,“百分比”意味着每一百只糖果。

Let’s look at an example.
::让我们举个例子。

If 25% of the people want chocolate cake, then 25 out of every 100 want chocolate cake. For this reason, percent can be written as a fraction with a denominator of 100.
::如果25%的人想要巧克力蛋糕,那么每100人中有25人想要巧克力蛋糕。因此,百分之二十五可以写成分数,分母为100。

$\begin{aligned} 25 % = \frac{25}{100} \end{aligned}$

Now, think about this again. Anytime you see a percent, you know that the amount is being compared to 100, or is “out of” 100.
::现在,再想想这个。当你看到百分之一的时候, 你知道这个数额是比100, 或者“超过”100。

Let’s look at another example.
::让我们再看看另一个例子。

Express 18% as a fraction.
::表示18%为分数。

Remember that a percent is a fraction with a denominator of 100.
::记住,1%是分数,分母为100。

$\begin{aligned} 18 % = \frac{18}{100} \end{aligned}$

Remember that a percent is a ratio compared to 100!
::记住,百分之一是比例与百比!

Examples
::实例

Example 1
::例1

Earlier, you were given a problem about Simon and his precipitation prediction.
::早些时候,你得到一个问题关于西蒙和他的降水预测。

According to Simon, there is a 70% chance of precipitation tomorrow. How can Simon explain what this percentage means?
::西蒙说,明天有70%的降水机会。西蒙如何解释这个百分比意味着什么?

First, remember that a percent is a fraction with a denominator of 100. Convert the percent into a fraction.
::首先,记住1%是一个分数,分母为100, 将百分比转换成一个分数。

$\begin{aligned} 70 % = \frac{70}{100} \end{aligned}$

Next, simplify the fraction.
::接下来,简化分数。

$\begin{aligned} \frac{70}{100} = \frac{7}{10} \end{aligned}$

The answer is you have a 7 out of 10 chance of getting wet if you go outside tomorrow.
::答案是,如果你明天去外面, 10个机会中就有7个有机会被湿透。

Example 2
::例2

Write the following as a percent.
::以下以百分比表示。

Carmen saw 100 movies in one year. She chose 60 of the movies as her favorites. The other 40 movies were not her favorites. Write her favorites as well as the other movies as a percent.
::卡门一年里看100部电影。她选择了60部电影作为她的最爱。其他40部电影不是她的最爱。她把最喜欢的电影和其他电影写成百分之一。

First, let’s write the favorites as a percent.
::首先,让我们把最喜爱的写成百分比。

Carmen chose 60 out of 100 as favorites. Therefore the percent can be written as 60%.
::卡门在100个中选择了60个为最爱。因此,60%的百分率可以写成为60%。

Next, write the movies that were not her favorites as a percent.
::接下来,写出那些不是她最喜欢的电影占百分之一。

Carmen did not choose 40 out of the 100 movies as favorites. Therefore the percent can be written as 40%.
::卡门没有在100部电影中选择40部作为最受欢迎的电影。因此,该百分比可以写成40%。

The answer is 60% of the movies were her favorites and 40% were not.
::答案是60%的电影是她的最爱,40%不是。

Example 3
::例3

Write as a percent: 23 out of 100.
::写作百分比:100人中有23人写作。

First, write the fraction to represent this problem.
::首先,写出代表这个问题的分数。

$\begin{aligned} 23 out to 100 = \frac{23}{100} \end{aligned}$

::23 至 100= 23100

Next, since a percent is a fraction with a denominator as 100, change the fraction into a percent.
::其次,由于一个百分比是分母为100的分母, 将分母改变为1%。

$\begin{aligned} \frac{23}{100} = 23 % \end{aligned}$

The answer is 23%.
::答案是23%。

Example 4
::例4

Write as a percent: 18.5 out of 100.
::写作百分比:100人中有18.5%是18.5%。

First, write the fraction to represent this problem.
::首先,写出代表这个问题的分数。

$\begin{aligned} 18.5 out of 100 = \frac{18.5}{100} \end{aligned}$

::100=18.5100中的18.5

Next, since a percent is a fraction with a denominator as 100, change the fraction into a percent.
::其次,由于一个百分比是分母为100的分母, 将分母改变为1%。

$\begin{aligned} \frac{18.5}{100} = 18.5 % \end{aligned}$

The answer is 18.5%.
::答案是18.5%。

Example 5
::例5

Write as a percent: 97 out of 100.
::写作百分比:100分中的97分。

First, write the fraction to represent this problem.
::首先,写出代表这个问题的分数。

$\begin{aligned} 97 out of 100 = \frac{97}{100} \end{aligned}$

::100=97100中97人

Next, since a percent is a fraction with a denominator of 100, change the fraction into a percent.
::其次,由于1%是分母100的分母, 将分母改变为1%。

$\begin{aligned} \frac{97}{100} = 97 % \end{aligned}$

The answer is 97%.
::答案是97%。

Review
::回顾

Write the following percent values as a ratio with a denominator of 100.
::将以下百分率值写成100分母的比率。

1. 64%

2. 3%

3. 119%

4. 4.7%

5. 88%

6. 99.5%

7. 12%

8. 14%

Write the following as a percent.
::以下以百分比表示。

9. 12 out of 100
::9. 100人中有12人

10. 13.5 out of 100
::10.5 占100人中的13.5

11. 87 out of 100
::11. 100人中有87人

12. 99 out of 100
::12. 100人中的99人

13. 5 out of 100
::13. 100人中有5人

14. 3.5 out of 100
::14.100人中有3.5人

15. 130 out of 100
::15 130人,100人

16. 175 out of 100
::16. 100人中的175人

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

Percents ::百分比

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
::百分比

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