Elapsed Time - PowerPoint Presentation

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Elapsed Time

A new way to calculate elapsed timeSlide2

Pennsylvania State Math Standard

PA Math Standard 2.3.3.C

Anchor M3.B.1.1Slide3

How do you figure out how much time has passed, or how much time will pass during a certain activity?

Do you…

Picture a clock in your head, and count through the hours and minutes with your fingers?Actually look at a clock, and count through the hours and minutes?Take a guess?Is there another way?????Slide4

The T-Chart Method

To use the T-Chart method to figure out elapsed time, first draw a T-Chart like the one below:Slide5

Let’s use the T-Chart to figure out this problem.

Brianna started her Algebra homework at 6:15. She finished at 6:50. How long did it take her to complete her homework?

First, identify your starting time by circling or highlighting it. Next, identify the ending time, and the question the problem is asking.On your T-Chart, put the starting time on the left hand side, and since we are only working with minutes this time ( We can see that it took Brianna less than 1 hour to complete her homework) write Minutes on the right hand side.Slide6

Next, add horizontal lines to your chart, and under the Minutes heading, list minutes in increments of 5, and stop at 55.Slide7

Under the left hand column where the starting time is listed, continue listing the time in 5 minute increments until you reach the stopping time (6:50)Slide8

When you have reached the stopping time, circle the time and the minutes listed on your T-Chart.Slide9

Now you can answer the question.

Brianna started her Algebra homework at 6:15. She finished at 6:50. How long did it take her to complete her homework?

It took Brianna 35 minutes to complete her homework.Slide10

The T-Chart Method

You can also use the T-Chart method to figure out elapsed time that includes hours and minutes by using 2 separate T-Charts.

Let’s try this problem:Ron sat down to draw at 5:10. He drew until 7:25. How long did Ron draw?Slide11

The T-Chart Method

First, identify your starting time and end time by circling or highlighting them.Next, identify what question the problem is asking.

Ron sat down to draw at 5:10. He drew until 7:25. How long did Ron draw?Slide12

Next, draw two T-Charts. On the first put the starting time, and Hours at the top. Slide13

As before, draw a few horizontal lines down your T-Chart. Under hours, start listing hours starting at 1. You can take a guess at how many hours you will need to list. What do you think?Slide14

Next, start listing the appropriate time next to each hour. Stop when you are close to the stopping time, but you have not gone past it.

Circle the time where you should stop. Which time listed below is close to the stopping time, but has not passed it?

*Remember that the stopping time is 7:25.Slide15

7:10 is close to the stopping time of 7:25, but is not past it. 8:10 would be too long because it went past the stopping time.

So now we can answer part of the question.

Ron drew for 2 hours. But how many minutes?Slide16

On your second T-Chart, write the time you reached after counting the hours (7:10) on the left. On the right, write Minutes.Slide17

As before, draw horizontal lines down your chart, and list minutes in increments of 5. Take a guess as to how many minutes you will need. If you need to add more minutes, you can always go back to add more.Slide18

Under the left hand column, continue listing the times in 5 minute increments until you reach the stopping time. (7:25). When you reach the stopping time, circle it.Slide19

Since the stopping time is 7:25, as we earlier identified, we can see that the number of minutes Ron spent drawing was 15 minutes.Slide20

We can now answer the entire question:

Ron sat down to draw at 5:10. He drew until 7:25. How long did Ron draw?

Ron drew for 2 hours and 15 minutes.Slide21

Let’s try another problem using analog clocks:

How much time has elapsed between the two clocks below?Slide22

First, identify the times on each clock:Slide23

Next, draw a T-Chart to figure out the time elapsed. Has more than an hour gone by? Then you will need 2 T-Charts.

Set up the first T-Chart labeled with the starting time, and Hours at the top.Slide24

Next, draw horizontal lines through your chart and list hours under the Hours column. How many hours do you think you’ll need?Slide25

Next, list the appropriate times next to each hour.

Which time is close to the stopping time (4:15) without going past it? Circle it.Slide26

Now you can answer the first part of the question. The elapsed time is one hour and…Slide27

Now, how many minutes have passed?

Draw your T-Chart labeled with the time you reached after finding the hours, (4:00) and Minutes at the top.

Draw the horizontal lines, and add minutes in 5 minute increments. Keep your stopping time in mind…how many minutes do you need to add?Slide28

Finally, add the correct times next to the corresponding minutes. Stop when you reach the ending time (4:15) Circle the time and minutes.Slide29

You can now completely answer the question. The elapsed time is:

One hour and 15 minutesSlide30

The T-Chart Method

Try finding the elapsed times using the analog clocks on the following slides. Create your own T-Charts to find the answers.Slide31
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The T-Chart Method

You can practice finding elapsed time further using these websites:http://www.shodor.org/interactivate/activities/ElapsedTime

/http://www.free-training-tutorial.com/telling-time-games.htmlhttp://www.harcourtschool.com/activity/elab2002/grade_3/018.html