secondsElapsed = 26789


hoursRemaining = secondsElapsed / 3600
               = 26789 / 3600 
               =    7
 
hoursRemainder = secondsElapsed - ( hoursRemaining * 3600 ) 
               = 26789 - ( 7 * 3600 ) 
               = 26789 - 25200
               =     1589


minutesRemaining = hoursRemainder / 60
                 =     1589       / 60 
                 =           26

secondsRemaining = hoursRemainder - ( minutesRemaining * 60 ) 
                 =     1589       - (        26        * 60 )
                 =     1589       -         1560 
                 =                29


secondsElapsed = (hoursRemaining * 3600) + (minutesRemaining * 60 ) + secondsRemaining
               = (    7          * 3600) + (     26          * 60 ) +     29
               =          25200          +            1560          +     29
               =        26789