Compute with Time
13-6
Find the elapsed time.
- from 3:15 P.M. to 6:30 P.M. 2. from 5:55 A.M. to 7:30 A.M.
- from 10:30 A.M. to 3:15 P.M. 4. from 9:20 A.M. to 1:30 P.M.
- from 5:16 A.M. to 9:35 A.M. 6. from 6:22 A.M. to 2:10 P.M.
60 seconds (s)1 minute (min)
60 min1 hour (h)
24 h1 day (d)
7 days1 week (wk)
12 months (mo)1 year (y)
365 d1 y
100 y1 century (cent.)
Tim’s watch reads 8:55 A.M. If he plans
to go to lunch at 12:00 P.M., how much
longer must he wait?
To find how much time longer, find the
elapsed time from 8:55 A.M.to 12:00 P.M.
You may use mental math or subtract
using paper and pencil.
Mental Math Paper and Pencil
5 10
From 8:55 A.M. to 9:00 A.M. is 5 min. 12:00 1 1 : 6 0
From 9:00 A.M. to 12:00 P.M. is 3 h. 0 8:55 0 8:5 5
The elapsed time is 3 h 5 min. 08:55 0 3:0 5
Tim must wait 3 h 5 min.
You can add to find the ending time of an event.
Pam boards the bus from her home at 12:15 P.M.If it takes 1 h 55 min to
reach her destination, at what time will Pam reach her destination?
To find the time, t, add: 12 h 15 min 1 h 55 min t.
12 h 15 min
1 h 55 min
13 h 70 min14 h 10 min 2:10 P.M.
Pam reaches her destination at 2:10 P.M.
Study these examples.
2 80
3 min 20 s
2 min 35 s
0 min 45 s45 s
8 wk 2 d
4
32 wk 8 d33 wk 1 d
3 y 8 mo 2
44 mo 2 22 mo
22 mo 1 y 10 mo
Regroup
1 h as 60 min.
3:05 3 h 5 min
2.0
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