Efectueaza:
5 h 45 min - 2 h 55 min = ?
19 h 30 min - 10 h 50 min = ?
8 h 15 min 30 sec - 4 h 25 min 45 sec = ?
5 h 35 min 20 sec - 2 h 50 min 50 sec = ?
Va rog sa va grabiti

Răspuns:

1| 2h.50min

2| 8h.40min

3| 3h.49min.45sec

4| 2h.44min.30sec

5 h 45 min - 2 h 55 min =

= 5 × 60 min + 45 min - 2 × 60 min - 55 min =

= 345 min - 175 min =

= 170 min =

= 1 h 50 min

19 h 30 min - 10 h 50 min =

= 1140 min + 30 min - 600 min - 50 min =

= 1170 min - 650 min =

= 520 min =

= 8 h 40 min

8 h 15 min 30 sec - 4 h 25 min 45 sec =

= 3600 × 8 sec + 15 × 60 sec + 30 sec - 3600 × 4 sec - 25 × 60 sec - 45 sec =

= 28800 sec + 900 sec + 30 sec - 14400 sec - 1500 sec - 45 sec =

= 29730 sec - 15945 sec =

= 13785 sec =

= 3h si ceva...

5 h 35 min 20 sec - 2 h 50 min 50 sec =

= 18000 sec + 2100 sec + 20 sec - 7200 sec - 3000 sec - 50 sec =

= 20120 sec - 10250 sec =

= 9870 sec =

= 2h si ceva...