SUM of two time columns


I have been tracking subitem work hours by using two intermediate columns and following formula:

SUM({Subitem Time Tracking},{Parent Item Time Tracking})/60/60

My questions:

  1. Is there a better method?
  2. Is there a way to add two time columns and output the result as a proper time format (not text!)

Thanks in advance!

I am also curious about this. My formula gives time in decimals but I would like it to be hours and minutes.