Elapsed time

key notes :

🎯 1. What is Elapsed Time?

  • Elapsed time is the amount of time that passes from the start time to the end time.
  • Example: If a movie starts at 3:00 PM and ends at 5:30 PM, the elapsed time is 2 hours 30 minutes.

🕒 2. Units of Time

  • 1 minute = 60 seconds
  • 1 hour = 60 minutes
  • 1 day = 24 hours
  • 1 week = 7 days

🔍 3. How to Calculate Elapsed Time

Method 1: Count Forward

  • Start at the beginning time and count forward to the end time.
  • Example: Start: 2:15 PM, End: 4:45 PM
    • From 2:15 PM to 4:15 PM = 2 hours
    • From 4:15 PM to 4:45 PM = 30 minutes
    • Total Elapsed Time = 2 hours 30 minutes

Method 2: Subtract Times

  • Write the end time above the start time and subtract.
    • Example:
      End time: 6:45 PM
      Start time: 3:30 PM
      6:45 – 3:30 = 3 hours 15 minutes

🔧 4. Word Problems

Example:
🚌 A bus leaves at 8:25 AM and arrives at 11:40 AM. How long is the trip?

  • From 8:25 AM to 11:25 AM = 3 hours
  • From 11:25 AM to 11:40 AM = 15 minutes
  • ✅ Elapsed Time = 3 hours 15 minutes

🧠 5. Tips & Tricks

  • Use number lines to visualize the time.
  • AM is from midnight to noon, PM is from noon to midnight.
  • When crossing over 12:00, remember 12:00 PM is noon and 12:00 AM is midnight.

Learn with an example

📢 It is now twenty-eight minutes past twelve. What time will it be in six hours and three minutes?

Write your answer using numbers and a colon (for example, 11:58).

Twenty-eight minutes past twelve means 12:28.

Count by hours to find 6 hours after 12:28. This is 6:28.
Now add 3 minutes to 6:28. This is 6:31.

It will be 6:31.

📢 It is now four minutes past twelve. What time will it be in six hours and thirty-eight minutes?

Write your answer using numbers and a colon (for example, 11:58).

Four minutes past twelve means 12:04.

Count by hours to find 6 hours after 12:04. This is 6:04.
Now add 38 minutes to 6:04. This is 6:42.

It will be 6:42.

📢 It is now five past six. What time will it be in 11 hours and 42 minutes?

Write your answer using numbers and a colon (for example, 11:58).

Five past six means 6:05.

Count by hours to find 11 hours after 6:05. This is 5:05.
Now add 42 minutes to 5:05. This is 5:47.

It will be 5:47.

Let’s practice!🖊️