1. Elapsed Time
Using Benchmarks

2. How long is the movie? I started watching a movie at
3:30 pm and it ended at 4:45 pm.

3. Elapsed Time
The movie started at 3:30 and ended at 4:45. How long was the movie?
+30 min
+30 min
+15 min
Strategy: Start at 3:30
and add time increments
to the hour or ½ hour,
(benchmarks), then
continue until end time.
3:30
4:00
4:30
4:45
= 75 minutes = 1 hour 15 minutes

4. How much time is there between school and bedtime?
How much time is there between the time school is out (3:40 pm) and bedtime (8:15 pm)?

5. Elapsed Time – using benchmarks
How much time is there between 3:40 and 8:15?
Strategy: Start at 3:40
and add time increments
to the ½ hour benchmarks,
then continue increments.
+20 min
+4 hours
+15 min
3:40
4:00
8:00
8:15
4 hours + 20 min min.= 4 hours 35 minutes

6. Time over the 12:00 hour
How much time is there between 10:30 am and 2:45 pm?

7. Elapsed Time – over 12 o’clock hour
How much time is there between 10:30 am and
2:45 pm?
+30 min.
+1 hour
+2 hours
+45 min
Strategy: Add increments
to 12:00, then continue
benchmark increments.
2:00
2:45
10:30
11:00
12:00
noon
1 hr. + 2 hr min min. = 3 hr. 75 min. = 4 hr. 15 min.

8. Find the ending time
What time is 4 hours and 30 minutes from 6:55?

9. Finding the ending time – Student 1
What time is it 4 hours and 30 minutes from 6:55?
Strategy: Add minute
increments to the ½ hour
benchmark, then hours, then
minutes.
+5 min
+4 hr.
+25 min
11:00
11:25
6:55
7:00
The time is 11:25, which is 4 hrs. and 30 min. after 6:55.

10. Finding the ending time – Student 2
What time is it 4 hours and 30 minutes from 6:55?
Strategy: Add hour increments
until close, then minutes to the
½ hour, then minutes.
+1 hr.
+1 hr.
+1 hr.
+1 hr.
+5 min
+25min
11:00
11:25
6:55
7:55
8:55
9:55
10:55
The time is 11:25, which is 4 hrs. and 30 min. after 6:55.

11. Find the start time
What time did we start on our trip if we arrived at 8:17 and it took 3 hours and 10 minutes?

12. Finding the start time The start time is 5:07. 5:07 5:17 8:17
What time did we start on our trip if we arrived at 8:17 and it took 3 hours and 10 minutes?
-10 min.
-3 hr.
Strategy: Subtract the hours
then minutes.
5:07
5:17
8:17
The start time is 5:07.

13. Find the start time
What time do I need to wake up if I have to be at school at 8:15 am and it takes me 1 hour and 45 minutes to get ready?

14. Finding the start time I have to wake up at 6:30 AM. 6:30 6:45 7:00
What time do I need to wake up if I have to be at school at 8:15 am and it takes me 1 hour and 45 minutes to get ready?
-1 hr.
-15 min.
-15 min.
-15 min.
Strategy: Subtract the hour,
then minute benchmarks.
6:30
6:45
7:00
7:15
8:15
I have to wake up at 6:30 AM.