To find when Carlos finished, you need to add both times. You can add whatever you prefer first. Let's say you add 53 first. Break down 53 into 50 and 3. 810 + 50 = 860. In time measurements it would be 9:00. Now add the 3 to 9:00, which is 9:03. Now we can add an hour. 9:03 + 1:00 (1 hour) = 10:03.
So Carlos finished at 10:03 A.M. Make sure to label A.M, or it will most likely be incorrect.
