Example of Sexagesimal System

The sexagesimal system comprises hours, minutes, and seconds. To perform the classical operations, that is, to add and subtract using the sexagesimal system, we must consider that the minutes and seconds cannot exceed the number sixty (60). It is also necessary to remember that 1 hour = 60 minutes and that 1 minute = 60 seconds.
Example of addition in the Sexagesimal System
In 1 hour and 15 minutes a track and field athletics competition will begin in the city of Guadalajara, Mexico. If the clock now strikes 6 hours and 55 minutes, what time exactly will the competition start?
6 h 55 m 00 s
+
1 h 15 m 00 s

7 h 70 m 00 s
The normal sum would give us 7 h 70 m 00 s, but as every time we pass 60, we write down the rest and transfer the times that groups of 60 were formed, that is, the final result for this example of addition is 8 h 10 m 00s. The mechanism is to separate the hours and minutes first, and then we start operations by the seconds.
Another example of addition:
A motorist covers a complete lap of the track in 19 minutes and 14 seconds. If you start the course at 17 hours, 12 minutes and 43 seconds, what time will you reach the finish line?

0 h 19 m 14 s
+
17 h 12 m 43 s

17 h 31 m 57 s
The answer for this example is that the motorist will reach the finish line at 17:31:57.
Example of subtraction in the Sexagesimal System
Marcelo is watching a live broadcast of a soccer game that lasted 1 hour, 33 minutes and 50 seconds. If 48 minutes and 20 seconds have already elapsed, how long will it take to finish?
1 h 33 m 50 s
-
48 m 20 s

0 h 45 m 30 s
In this example we cannot subtract 33 minutes - 48 minutes, so we must take or "borrow" 60 minutes to the factor of the hours. Then we will have 60m + 33m = 93m left, and then we can do the subtraction. Keep in mind that in the sexagesimal system 60 "lend".
Another example of subtraction:
An ice skate exhibition ended at 16:15. If the show lasted 2 hours and 25 minutes, what time did it start?
We solve it with the following operation:


16 h 15 m 00 s
-
2 h 25 m 00 s


13 h 50 m 00 s
The answer for this subtraction example is 13 hours and 50 minutes.
When we add or subtract using the sexagesimal system, the order of minutes and seconds does not have to exceed the number 60. And remember also to separate the hours, minutes and seconds and start the operations by the seconds.