6.15运行时间

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  运行时间

  

  [Figure 1]

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  James is reading a book. He started at 4:00 p.m. and before he knew it, it was 8:30 p.m. How much time did James spend reading?
  ::詹姆斯在读一本书 他从下午4点开始 在他知道之前是晚上8点30分

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  In this concept, you will learn how to find  elapsed time .
  ::在这个概念中,你将学会如何找到时间。

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  Calculating Elapsed Time
  ::计算折余时间

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  Elapsed time  is the amount of time that has passed between two events. You can calculate the elapsed time by figuring out the difference between the start and stop time.
  ::错开的时间是两个事件之间的时间间隔。 您可以通过了解开始时间和停止时间之间的差数来计算时间间隔 。

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  Here is an elapsed time problem.
  ::这是一个时间过长的问题。

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  Soccer practice begins at 3:15 p.m. and ends at 4:45 p.m. Determine how long soccer practice lasts.
  ::足球练习从下午3时15分开始,下午4时45分结束。 确定足球练习持续多久。

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  To solve this problem, set up a subtraction problem that could be used to find the number of hours and minutes that pass between those two times.
  ::为了解决这个问题,设置一个减法问题,可以用来查找这两次之间的时数和分钟数。

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  Subtract the starting time from the stopping time. Remember that both times represent the number of hours and minutes past noon. 
  ::将开始时间从停止时间中减去。 记住, 两次代表中午前的小时数和分钟数 。

  $$\begin{array}{r}4:45\\ \underset{\_}{-3:15}\\ 1:30\end{array}$$

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  Soccer practice lasts for 1  hour  30 minutes.
  ::足球练习持续1小时30分钟

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  Here is another problem.
  ::还有一个问题。

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  A dance performance starts at 7:30 p.m. and ends at 10:10 p.m. How long does the performance last?
  ::舞蹈表演从下午7时30分开始,到晚上10时10分结束。 表演持续多久?

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  Subtract the starting time from the stopping time. 
  ::将起始时间从停止时间减为开始时间 。

  $$\begin{array}{rl}& 10:10\\ & \underset{\_}{-7:30}\end{array}$$

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  You cannot subtract 30 minutes from 10 minutes, so you must rewrite 10:10. Remember, 10:10 stands for 10 hours 10 minutes. Borrow from the hour unit. 1 hour equals 60 minutes. Add 60 minutes to the 10 minutes. 
  ::您不能从 10 分钟中减去 30 分钟, 所以您必须重写 10: 10 分钟 。 记住, 10: 10 10 分钟代表 10 小时 10 分钟 。 从 小时单位借款 。 1 小时等于 60 分钟 。 加上 60 分钟 到 10 分钟 。

   

  $$\begin{array}{rl}{\cancel{10}}^9& :{\cancel{10}}^{70}\\ -7& :30\\ 2& :40\end{array}$$

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  Events can also occur before noon (a.m.) and end after noon (p.m.). When that happens, finding the elapsed time requires an additional step. This is a result of using a 12-hour clock.
  ::事件也可能发生在中午之前(上午)和中午之后(下午),如果发生这种情况,需要额外一步才能找到已过的时间。这是使用12小时钟的结果。

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  Here is an example.
  ::举一个例子。

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  John goes to school at 8:00 a.m. and returns home at 3:00 p.m. How long was John at school?
  ::约翰早上8点上学 下午3点回家 约翰上学多久了?

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  You might think that the elapsed time is 5 hours, which would be incorrect. Before finding the difference, add 12 hours to 3:00 p.m. 
  ::你可能会认为过去的时间是5小时,这是不正确的。在发现差额之前,再加12小时到下午3时。

  $$\begin{array}{r}12:00\\ +1:40\\ 13:40\end{array}$$

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  Remember that the day starts at midnight. 8:00 a.m. is 8 hours into the day and 3:00 p.m. is actually 15 hours into the day. Rewrite 3:00 p.m. as 15:00 and find the elapsed time. 
  ::记得白天从午夜开始,早上8点是每天8小时,下午3点实际上是每天15小时。 下午3点重写为下午3点,找到时间。

  $$\begin{array}{r}15:00\\ -8:00\\ 7:00\end{array}$$

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  John was at school for 7 hours. 
  ::约翰在学校呆了7个小时

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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 James reading his book.
  ::早些时候,你被问及 詹姆斯读他的书的问题。

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  James started at 4:00 p.m. and stopped at 8:30 p.m. Find the elapsed time between the start and end time.
  ::詹姆斯下午4时开始,晚上8时30分停止。 找到从开始到结束的时间间隔。

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  Subtract the start time from the end time. 
  ::从结束时间减去开始时间 。

  $$\begin{array}{rl}& 8:30\\ & -4:00\\ & 4:30\end{array}$$

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  James spent 4 hours 30 minutes reading.
  ::James花了4小时30分钟阅读。

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  Example 2
  ::例2

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  Find the elapsed time.
  ::寻找已过去的时间 。

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  The soccer game started at 10:00 a.m. and ended at 1:40 p.m. How long was the game?
  ::足球比赛于上午10时开始,下午1时40分结束。 比赛持续了多久?

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  The start and stop time occur during different parts of the day, a.m. and p.m.
  ::开始和停止时间发生在一天的不同时间,上午和下午。

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  First, rewrite 1:40 pm. Add 12 hours to the p.m. time. 
  ::首先,改写下午1时40分,加上12小时到下午的时间。

  $$\begin{array}{rl}& 12:00\\ & \underset{\_}{+1:40}\\ & 13:40\end{array}$$

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  Then, subtract the start time from the end time.
  ::然后,从结束时间减去起始时间。

  $$\begin{array}{rl}& 13:40\\ & \underset{\_}{-10:00}\\ & 3:40\end{array}$$

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  The game was 3 hours 40 minutes long.
  ::比赛持续了3小时40分钟

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  Example 3
  ::例3

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  The game started at 9:10 am and ended at 11:15 am. What was the  length  of the game?
  ::游戏于上午9: 10开始,于上午11: 15结束。游戏的长度是多少?

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  Subtract the start time from the end time. 
  ::从结束时间减去开始时间 。

  $$\begin{array}{rl}& 11:15\\ & -9:10\\ & 2:05\end{array}$$

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  The elapsed time is 2 hours and 5 minutes.
  ::时间已过去2小时5分钟。

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  Example 4
  ::例4

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  The movie started at 7:30 pm and ended at 10:20 pm. How long was the movie?
  ::电影于下午7: 30开始, 于晚上10: 20结束。 电影持续了多久?

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  Subtract the start time from the end time. Borrow 60 minutes from the hour place value. 
  ::减去从结束时间开始的时间。 从小时位置值中借款60分钟 。

  $$\begin{array}{rl}{\cancel{10}}^9& :{\cancel{20}}^{80}\\ -7& :30\\ 2& :50\end{array}$$

  
  

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  The elapsed time is 2 hours and 50 minutes.
  ::时间已过去2小时50分钟。

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  Example 5
  ::例5

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  Jake walked from 7:15 am until 9:00 am. How long was his walk?
  ::杰克从早上7点15分走到早上9点 他走了多久?

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  Subtract the start time from the end time. Borrow 60 minutes from the hour place value.
  ::减去从结束时间开始的时间。 从小时位置值中借款60分钟 。

   

  $$\begin{array}{rl}{\cancel{9}}^8& :{\cancel{00}}^{60}\\ -7& :15\\ 1& :45\end{array}$$

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  The elapsed time is 1 hour and 45 minutes.
  
  ::时间已经过了一小时45分钟。

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  Review
  ::回顾

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  Calculate the elapsed time in each problem.
  ::计算每个问题的时间间隔 。

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  1. If a movie starts at 7:15 p.m. and ends at 9:20 p.m., how long was the movie?
     ::如果电影在下午7点15分开始 晚上9点20分结束 那电影要拍多久?
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  2. If a movie starts at 7:15 p.m. and ends at 9:20 p.m., but has ten minutes of previews, how long is the movie?
     ::如果一部电影于下午7点15分开拍, 于晚上9点20分结束, 但有十分钟的预览,
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  3. If a movie was 1 hour and 50 minutes and started at 8:00 p.m., what time would the movie end?
     ::如果一部电影1小时50分钟 于下午8点开始,电影什么时候结束?
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  4. If there were an additional 15 minutes of previews in this movie, what time would the movie end?
     ::如果这部电影还有15分钟的预演 电影什么时候会结束?
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  5. If there was also a 10 minute intermission, what time would the movie end?
     ::如果还有十分钟的中场休息,电影什么时候结束?
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  6. A hike lasted for 2 hours. If it started at 8:20 a.m., what time did it end?
     ::徒步持续了两个小时,如果从上午8时20分开始,是什么时候结束的?
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  7. A hike lasted for 3 hours and 5 minutes. If it started at 9:05 a.m., what time did it end?
     ::持续了3小时5分钟,如果从上午9: 05开始,何时结束?
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  8. A walk started at 7:09 a.m. and went until 10:45 a.m. How long was the walk?
     ::上午7时09分开始散步,持续到上午10时45分。
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  9. If a movie starts at 5:15 p.m. and ends at 6:20 p.m., how long was the movie?
     ::如果电影下午5点15分开始 6点20分结束 那电影要多久?
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  10. Jesse rode his bike from 8:00 p.m. until 9:07 p.m., how long did he ride?
      ::杰西从晚上8点骑自行车到晚上9点07分 他骑了多久?
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  11. Jesse went swimming from 9:07 a.m. until 10:03 a.m., how long did he swim?
      ::杰西从上午9: 07一直游泳到上午10: 03, 他游泳多久了?
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  12. If Marcy went swimming twice as long as Jesse, how long did she swim?
      ::如果玛西游泳比杰西长一倍 她游泳多久了?
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  13. Caleb went swimming half as long as Jesse, how long did he swim?
      ::Caleb游泳了一半 只要Jesse,他游泳了多久?
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  14. Samuel attended an assembly that lasted for four hours. If it started at 8:32 a.m., what time did it end?
      ::Samuel参加了一个持续四个小时的集会,如果从上午8时32分开始,是什么时候结束的?
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  15. If the Campbell family went to the beach for 5 hours and 11 minutes and they left the beach at 7:00 p.m., what time did they arrive?
      ::如果Campbell一家去海滩5小时11分钟 晚上7点离开海滩 他们什么时候到的?

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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