Today is . WELCOME: chenyaoyuan/44669  Home | Reg LoginAll user | setHomePage | Bookmark  
Home | Math Test Online | Addition | Subtraction | Multiplication | Division | Time | Worksheet(JPG/PDF) | CAI
 Recommendation article
 Article search
 
 Home--maths--Third Grade--Add half hours

Add half hours

Addition of Time

How to add hours and half-hours to a time:

  • Add the number of minutes together. If the minutes are 60 or more, subtract 60 from the minutes and increase the number of hours by one.
  • 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 17 hours and 30 minutes after 3:30 AM?

  • The sum of the minutes equals 60. Subtract 60 from the minutes and increase the hours by one to 18.
  • Add the hours together. (18 hours + 3 hours = 21 hours)
  • If the number of hours is more than 12 do the following:
    • Subtract 12 from the number of hours. (21 hours - 12 hours = 9 hours)
    • Change the AM to PM.
  • Answer: 9:00 PM


What is the Sum of the times?


 





2006-11-18 22:42:53
Viewed 1523 times Close
Math Test Online Greatmathsites

Translate

Arabic  Chinese  French  German  Italian  Japanese  Korean  Portuguese  Spanish

Feedback
Thank you to online math channels' Mathematics Department for hosting these lessons.
Copyright © 2006 - 2008 GZtrain Inc. All Rights Reserved