Addition of Time

How to add hours to a time:

  • Add the number of hours to the hours portion of the time.
  • If the number of hours is more than 12 do the following:
    • Subtract 12 from the number of hours.
    • If the time was AM change it to PM, if it was PM change it to AM.
    • Repeat this process if the number of hours is still more than 12.
  • If the number of hours is equal to 12 change AM to PM or PM to AM.

Example: What time is 16 hours after 9:00 AM?

  • Add the hours together. (16 hours + 9 hours = 25 hours)
  • If the number of hours is more than 12 do the following:
    • Subtract 12 from the number of hours. (25 hours - 12 hours = 13 hours)
    • Change the AM to PM.
    • Repeat this process if the number of hours is still more than 12.
    • Subtract 12 hours from 13 hours. Change the PM to AM.
  • Answer: 1:00 AM







What is the Sum of the times?