Elapsed Time
Basics on the topic Elapsed Time
Zuri and Freddie are participating in a scavenger hunt to win tickets to the big movie premiere! Not only do they have to find the clues, but they also have to calculate how long it took, or the elapsed time, to find each one. They need your help calculating elapsed time using a T chart!
Transcript Elapsed Time
Zuri and Freddie are participating in a scavenger hunt to win tickets to the big movie premiere. They need to find three clues, AND calculate how long it takes to find each one. Let's calculate the "elapsed time" it took them to find the first clue. "Elapsed time is how much time has passed or gone by from one point to another". Some intervals we can use to calculate elapsed time are one minute, five minutes, ten minutes, fifteen minutes, thirty minutes, and more! One tool we can use to calculate elapsed time is a T chart, like THIS. The first step is to label the START time and the END time. The scavenger hunt began at twofifteen, so write the start time HERE. They found the clue at three o'six, so write the end time HERE. The second step is to record time intervals on the T Chart until the END time is reached. There are many intervals we can choose to add, but if we choose intervals that end on the half or full hour, it makes choosing the next interval easier. Let's add fifteen minutes first abbreviating minutes with 'min'. Twofifteen plus fifteen minutes is twothirty so record that HERE. Add thirty minutes next recording it HERE. Thirty minutes after twothirty is... three o'clock, which goes HERE. Last, we add six minutes to three to reach three o'six. Now that the END time is reached, we can move to the third step... which is to ADD the elapsed time in the RIGHT column. Fifteen PLUS thirty PLUS six is fiftyone it took fiftyone minutes to find the first clue. Freddie and Zuri are looking for the second clue in the ice cream shop. Oh! They found it! Let's calculate the elapsed time it took them to find the second clue. The first step is to label the START time and the END time. They began searching at threeten and found the clue at three fortyeight. The second step is to record time intervals on the T Chart until the END time is reached. Remember, we want to try to reach the half or full hour to make adding the intervals easier. Begin with twenty minutes. What time is twenty minutes after threeten? Threethirty so write the new time HERE. Look at the END TIME, what would you add now? Ten minutes to get three forty, how much time should we add next? Eight minutes, to reach our END TIME of three fortyeight. What is the third step? Add the elapsed time in the RIGHT column. What is the elapsed time it took to find the second clue? Twenty PLUS ten PLUS eight is thirtyeight it took thirtyeight minutes. Zuri and Freddie are looking for the last clue. It sure is taking them a long time to find this clue! Woooohooo! There it is! It looks like tickets to the movie premiere! Before they go, let's calculate the elapsed time it took to find the last clue. What is our first step? First, label the START time and END time. They began searching at four o'five and found the clue at five sixteen. What is the second step? The second step is to record time intervals on the T Chart until the END time is reached. This time, try adding on your own. You could've added one hour FIRST using the abbreviation
Elapsed Time exercise

How long was the movie?
HintsTo figure out the length of the movie, add up the elapsed time on the right side of the chart.
How many hours and how many minutes altogether?
SolutionThe movie was 1 hour and 45 minutes long.
If we add 10 + 30 + 5 we get 45.
1 hour plus 45 minutes is 1 hour 45 minutes.

How long did it take Freddie and Zuri to get home?
HintsCalculate how many hours or minutes have passed between each set of times on the left side of the chart.
Put the total elapsed time at the bottom by adding the time intervals on the right side of the chart.
SolutionThe elapsed time of the bus journey was 1 hour and 15 minutes.
 8:25  9:25 is 1 hour
 9:25  9:30 is 5 minutes
 9:30  9:40 is 10 minutes
 5 minutes + 10 minutes = 15 minutes
 1 hour + 15 minutes = 1 hour 15 minutes

Which movie do Freddie and Zuri have time to watch?
HintsAre any of the movies over 2 hours? Remember, Freddie and Zuri only have 1 hour and 50 minutes.
You could draw your own chart like this and add small intervals of time to figure out which film they have time to watch.
SolutionFreddie and Zuri have time to watch Breezy Beachball!
It starts at 1:55 and ends at 3:45, so the elapsed time is 1 hour 50 minutes.
 If we add 1 hour to 1:55 we get to 2:55.
 We could then add on 5 minutes to get to 3:00.
 Next, we could add on 45 minutes to get to 3:45.
 If we add 45 + 5 we get 50.
 1 hour + 50 minutes = 1 hour 50 minutes.

How long did each activity take?
HintsStart by adding hours if you can, like in this example.
Remember, add minutes to the hour or half hour to help you figure out what to add next, like in this example.
SolutionFreddie and Zuri spent:
 1 hour 45 minutes cleaning.
 55 minutes shopping.
 50 minutes gardening.
 1 hour 20 minutes cooking.
Cleaning
 Starting at 9:20 we add on 1 hour to get to 10:20.
 We can then add on 10 minutes to get to 10:30.
 Then add on 30 minutes to get to 11:00.
 Finally 5 minutes to get to 11:05.
 Add 10 + 30 + 5 to get 45 minutes.
 1 hour + 45 minutes = 1 hour 45 minutes.
 First, add 5 minutes to get to 11:30.
 Then add on 30 minutes to get to 12:00.
 Finally add on 20 minutes to get to 12:20.
 5 + 30 + 20 = 55 minutes.
 First add on 25 minutes to get to 5:00.
 Then add on another 25 minutes to get to 5:25.
 25 + 25 = 50 minutes.
 Start by adding 1 hour to get to 7:05.
 We could then add on 20 minutes to get to 7:25.
 1 hour + 20 minutes = 1 hour 20 minutes.

How long was the TV show?
HintsAdd the intervals of time on the right side of the chart to find the total elapsed time.
Is the the TV show more than or less than an hour?
SolutionThe TV show was 35 minutes.
If we add 20 and 15 we get 35, so the elapsed time of the show was 35 minutes.

Are the elapsed times correct?
HintsTry drawing your own chart to help you figure out the elapsed times.
Add hours and then minutes in intervals to help you figure out the elapsed time.
SolutionHere are the errors that should have been highlighted.
9:17  10:43
 Here the minutes were incorrect. This should have been 1 hour and 26 minutes.
 If we add 1 hour to 9:17 we get to 10:17.
 We can then add 3 minutes to get to 10:20.
 Then 10 minutes to get to 10:30.
 Then 10 minutes to get to 10:40.
 And 3 minutes to get to 10:43.
 3 + 10 + 10 + 3 = 26. 1 hour + 26 minutes = 1 hour and 26 minutes.
 This one is correct.
 If we add 1 hour to 9:26 we get to 10:26.
 We can then add 4 minutes to get to 10:30.
 Then 20 minutes to get to 10:50.
 And 2 minutes to get to 10:52.
 4 + 20 + 2 = 26. 1 hour + 26 minutes = 1 hour and 26 minutes.
 Here the hours were incorrect. This should have been 1 hour and 13 minutes.
 If we add 1 hour to 9:51 we get to 10:51.
 We can then add 9 minutes to get to 11:00.
 And 4 minutes to get to 11:04.
 9 + 4 = 13. 1 hour + 13 minutes = 1 hour and 13 minutes.
 Here the hour and minutes were both incorrect. This should have been 1 hour and 14 minutes.
 If we add 1 hour to 10:13 we get to 11:13.
 We can then add 2 minutes to get to 11:15.
 Then 10 minutes to get to 11:25.
 And 2 minutes to get to 11:27.
 2 + 10 + 2 = 14. 1 hour + 14 minutes = 1 hour and 14 minutes.
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