How to subtract minutes and seconds

• If the number of seconds being subtracted is more than the original seconds, do the following:
  • Subtract 1 from the original number of minutes.
  • Increase the number of original seconds by 60.
• Subtract the seconds.
• Subtract the minutes.

Example: What is 4 minutes 11 seconds minus 2 minutes 47 seconds.

• The original number of seconds (11) is less than the 47 seconds being subtracted so:
  • Subtract 1 from the original number of minutes. (4 minutes - 1 minute = 3 minutes)
  • Increase the number of seconds by 60. (11 seconds + 60 seconds = 71 seconds)
• Subtract the seconds. (71 seconds - 47 seconds = 24 seconds)
• Subtract the minutes. (3 minutes - 2 minutes = 1 minute)
• Answer: 1 minute 24 seconds