time calculations

I seem to have had a brain malfunction as I don't seem to be able to do time calculations anymore. I am attempting to use Excel for this, but I have no idea how to perform the calculations I need. As example, I know that 4:00 (hours) 4 times is 16:00 (hours). Based on this, and knowing that minutes are counted in groups of 60 (no minute is counted as 61 or higher), I know that 3:58 3 times and 3:59 all added together is 15:53 minutes. What I don't know is how to do that addition. My brain keeps failing me when it comes to converting the minutes to hours and getting the correct number of minutes. What I mean is, 58+58+58+59 does not result in a minute value of 53 minutes and I can't remember how to calculate it. I would appreciate a refresher in time calculations, with examples of using Excel to perform them.

Formula+Custom format

Formula:

Please Login or Register  to view this content.