估算技巧

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Shen and his family went to a restaurant to celebrate his last day of school. When the bill arrived the total came to $45.20. Shen knows they are supposed to leave a  tip  on the total  amount . How much of a tip should they leave and what is the total amount of the bill including the tip?
::Shen和他的家人去一家餐馆庆祝他最后一天的学校。当法案到达时,总金额达到45.20美元。 Shen知道他们应该给总额留一个小费。他们应该离开多少小费以及包括小费在内的总金额是多少?

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In this concept, you will learn to estimate appropriate tips.
::在这一概念中,你会学会估计适当的小费。

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Estimating Tips
::估算提示

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A  tip  is an amount of money that is given to a worker, such as a waiter or luggage handler, who performs a service for you. A common tip amount is 15% of the cost of the meal or other service. Since you don’t usually calculate a tip exactly, you can estimate the amount of a tip.
::提示是给一个为您提供服务的工人(如服务员或行李处理员)的一笔金额。 通常的提示金额是餐费或其他服务费的15%。 由于您通常不精确计算提示,您可以估算提示金额。

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Follow these steps to estimate a 15% tip:
::遵循这些步骤来估计15%的提示 :

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First,  round  the total bill to the nearest whole dollar amount.
::首先,将总帐单转至最近的整美元数额。

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Next, find 10% of this amount by moving the  decimal point  one place to the left.
::下一步,通过将小数点一移到左边,找到这个数额的10%。

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Now, find half of the amount you found in Step 2. This will give you 5% of the total cost.
::现在,找到你在第二步中发现的一半金额, 相当于总成本的5%。

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Then, add the 10% amount and the 5% amount together. This will give you your total tip.
::然后加上10%的金额和5%的金额。这会给你总的小费。

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Let’s apply these steps by taking a look at an example.
::让我们以身作则来运用这些步骤。

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Estimate a 15% tip on a meal that costs $29.75.
::估计一顿饭要花15%的小费 需要29.75美元

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First, round $29.75 to $30.
::第一轮,29.75美元到30美元

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Next, find 10% of  $\begin{array}{r}\$30=\$3.00\end{array}$
::下一个,发现 30美元的10% = 3.00美元

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Now, find half of 10%: Half of  $\begin{array}{r}\$3.00=\$1.50\end{array}$
::现在,找到10%的一半:3.00美元=1.50美元的一半。

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Then, add 10% and 5%:  $\begin{array}{r}\$3.00+\$1.50=\$4.50\end{array}$

::然后,加上10%和5%:3.00美元+1.50美元=4.50美元

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A 15% tip on a meal that costs $29.75 is about $4.50.
::15美分的一顿饭 花费29.75美元 大约是4.50美元

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Let’s take a look at another example.
::让我们看看另一个例子。

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A tip doesn’t always have to be 15%. It can be more or less depending on the level of service you received. If your waitress was especially good you may decide to give her a bigger tip. Estimate a 20% tip on a restaurant bill of $38.95.
::提示并不一定总是15 % 。 它可能或多或少取决于您得到的服务水平。 如果服务员表现特别好,您可以决定给她一个更大的提示。 一份38.95美元的餐厅账单上大约20%的提示。

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You can start by thinking about 10% of this bill. Since that involves simply moving the decimal point, you can say that the estimate of 10% is $3.90.
::你可以首先考虑10%的帐单。因为这意味着只需移动小数点,你可以说10%的估计数是3.90美元。

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Now 20% is double that to $7.80.
::现在20%是两倍到7.80美元

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You can say that an estimate of a 20% tip is in a range from  $\begin{array}{r}\$7.50-\$8.00\end{array}$ .
::你可以说,20%的小费的估计数在7.50美元到8.00美元之间。

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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 Shen’s end-of-school celebration meal.
::更早之前,

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The total of the family’s bill came to $45.20. How much of a tip should they leave and what is the total amount of the bill including the tip?
::家庭法案总额达到45.20美元。 他们应该离开多少小费以及包括小费在内的法案总额是多少?

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Recall that the tip should be based on the level of service received. For good service you should leave 15%. For exceptional service, you might want to leave 20%.
::请注意,提示应该基于所接受的服务水平。如果服务良好,您应该离开15%。对于特殊服务,您应该离开20%。

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First, round $45.20 to $45.00.
::第一轮45.20到45.00

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Next, find 10% of  $\begin{array}{r}\$45=\$4.50\end{array}$
::接下来,发现45美元=4.50美元的10%

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Now, find half of  $\begin{array}{r}\$4.50=\$2.25\end{array}$
::现在,找到一半的4.50美元=2.25美元。

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Then, for a 15% tip add  $\begin{array}{r}10\mathrm{\%}+5\mathrm{\%}:\$4.50+\$2.25=\$6.75\end{array}$
::然后,对于15%的小费,加上10%+5%:4.50美元+2.25美元=6.75美元

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Finally, for 20% double 10%:  $\begin{array}{r}2(4.50)=\$9.00\end{array}$
::最后,20%翻一番,10%:2(4.50)=9.00美元

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The answer is Shen's family should leave a tip between $6.75 and $9.00, so the total amount of their bill, including tip, is between  $\begin{array}{r}\$51.95(\$45.20+\$6.75)\end{array}$  and  $\begin{array}{r}\$54.20(\$45.20+\$9.00)\end{array}$ .
::答案是沈家家应该留下6.75美元到9.00美元之间的小费,因此他们的账单总额,包括小费在内,在51.95美元(45.20美元+6.75美元)和54.20美元(45.20美元+9.00美元)之间。

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Example 2
::例2

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Estimate a 20% tip on a meal that costs $54.15.
::估计一顿需要54.15美元的饭 需要20%的小费

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Since the tip is about 20%, you can find 10% and then double it.
::因为小费大约是20%, 你可以找到10%,然后翻倍。

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First, round $54.15 to $54.
::第一,54.15美元到54美元

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Next, find 10% of  $\begin{array}{r}\$54=\$5.40\end{array}$
::接下来,发现54美元=5.40美元的10%

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Then, find 20% of  $\begin{array}{r}\$54=2\times \$5.40=\$10.80\end{array}$
::然后,发现54美元=2x5.40美元=10.80美元的20%

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A 20% tip on a meal that costs $54.15 is about $10.80.
::20%的餐费54.15美元 大约是10.80美元

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Example 3
::例3

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Estimate a 15% tip for a $29.00 bill. Provide a range in your answer.
::估计一张29.00美元的帐单有15%的提示。在您的答复中提供一个范围 。

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First, $29.00 is already rounded.
::首先,29.00美元已经四舍五入了

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Next, find 10% of  $\begin{array}{r}\$29=\$2.90\end{array}$
::接下来,发现29美元=2.90美元的10%

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Now, find half of  $\begin{array}{r}\$2.90=\$1.45\end{array}$  
::现在,找到290美元=1.45美元的一半

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Then, add 10% and 5%:  $\begin{array}{r}\$2.90+\$1.45=\$4.35\end{array}$
::然后,加上10%和5%:2.90美元+1.45美元=4.35美元

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A 15% tip on a meal whose cost is $29.00 is between $4.00 and $4.50.
::15美分的餐费为29.00美元,在4.00至4.50美元之间。

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Example 4
::例4

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Estimate a 15% tip for a $16.00 bill. Provide a range in your answer.
::$16. 00 帐单的15%的提示。 在您的答复中提供一个范围 。

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First, $16.00 is already rounded.
::首先,$16.00已经四舍五入。

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Next, find 10% of  $\begin{array}{r}\$16=\$1.60\end{array}$  
::下一步,发现16美元=1.60美元的10%

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Now, find half of  $\begin{array}{r}\$1.60=\$0.80\end{array}$  
::现在,找出1.60美元=0.80美元的一半

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Then, add 10% and 5%:  $\begin{array}{r}\$1.60+\$0.80=\$2.40\end{array}$
::然后,加上10%和5%:1.60美元+0.80美元=2.40美元

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A 15% tip on a meal that costs $16.00 is between $2.00 and $2.50.
::15美分的一顿饭 价钱16.00美元 介于2美元到2.50美元之间

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Example 5
::例5

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Estimate a 15% tip for a $55.00 bill. Provide a range in your answer.
::估计55.00美元的帐单有15%的提示。在您的答复中提供一个范围 。

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First, $55.00 is already rounded.
::首先,55.00美元已经四舍五入。

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Next, find 10% of  $\begin{array}{r}\$55=\$5.50\end{array}$
::接下来,发现55美元=5.50美元的10%

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Now, find half of  $\begin{array}{r}\$5.50=\$2.75\end{array}$  
::现在,找到5.50美元=2.75美元的一半

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Then, add 10% and 5%:  $\begin{array}{r}\$5.50+\$2.75=\$8.25\end{array}$
::然后,加上10%和5%:5.50美元+2.75美元=8.25美元

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A 15% tip on a meal that costs $55.00 is between $8.00 and $8.50.
::15美分的一顿饭费55.00美元 在8.00美元到8.50美元之间

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Review
::回顾

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Estimate a tip of 20% for each amount.
::估计每笔金额的点数为20%。

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1. A tip on $15.00
   ::$15.00的小费
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2. A tip on $28.00
   ::28.00美元一小费
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3. A tip on $25.00
   ::25.00美元的小费
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4. A tip on $35.00
   ::关于35.00美元的小费
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5. A tip on $45.00
   ::45.00美元的小费
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6. A tip on $50.00
   ::50.00美元的小费
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7. A tip on $90.00
   ::$90.00的小费$90.00
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8. A tip on $120.00
   ::$120美元上一个小费$120.00
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9. A tip on $125.00
   ::$125.00的小费$125.00$
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10. A tip on $110.50
    ::110.50美元的小费
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11. A tip on $130.75
    ::130.75美元的小费
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12. A tip on $135.50
    ::关于135.50美元的小费
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13. A tip on $98.78
    ::关于9878美元的情报
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14. A tip on $89.67
    ::89.67美元的小费
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15. A tip on $100.20
    ::有关100元的线报 20

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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