Answer:
You do a interger division, minutes divided by 60, keeping in mind integers do not use decimal points. The integer result is the hours. Then you do a remainder or Modulus (%) of the minutes by 60 to get the remainder in minutes.
Java:
Int hours, minutes=140, minutesresults;
hours=minutes/60; //result is 2 hours
minutesresults=minutes%60; //result is 20 minutes
Calculator:
A calculator is normally not equipped to do an integer division directly. Dividing 140/60 gives you 2.333. The 2 becomes the hours then take the decimal part (.33) and multiply it by 60 (result 19.8 or 20 rounded to an integer value is the minutes).