Class 5 >> Math >> measurement >> time-intervals >> calculate-durations-in-contexts-like-travel-and-schedules
Skip to Practice

calculate-durations-in-contexts-like-travel-and-schedules

🚀 Measurement of time intervals is an important concept that helps us understand how long events take. In everyday life, we often need to calculate durations, such as how long a trip will take or how long we have until an event starts. This involves understanding the units of time (seconds, minutes, hours) and how to add or subtract these units to find the total duration. For example, if a train leaves at 2:00 PM and arrives at 3:30 PM, we can calculate the duration of the trip by subtracting the start time from the end time.

Theory Explanation

Understanding Time Units

Time is measured in units such as seconds, minutes, and hours. There are 60 seconds in a minute and 60 minutes in an hour. Knowing these conversions is essential for calculating durations.

Calculating Durations

To calculate the duration between two times, subtract the start time from the end time. If the end time is earlier than the start time, you may need to add 24 hours to the end time to get the correct duration.

Using a Timeline

Visualizing time on a timeline can help in understanding how to calculate durations. Mark the start and end times on the timeline and count the intervals between them.

Key Points

  • 🎯 Time is measured in seconds, minutes, and hours.
  • 🎯 To find the duration, subtract the start time from the end time.
  • 🎯 If the end time is earlier than the start time, add 24 hours to the end time before subtracting.

Examples:💡

A bus leaves at 10:15 AM and arrives at 11:45 AM. How long is the bus ride?

Solution:

Step 1: Identify the start time (10:15 AM) and the end time (11:45 AM).

Step 2: Subtract the start time from the end time: 11:45 AM - 10:15 AM.

Step 3: Convert the times to minutes: 11:45 AM is 705 minutes and 10:15 AM is 615 minutes.

Step 4: Calculate the difference: 705 - 615 = 90 minutes.

Step 5: Convert 90 minutes back to hours and minutes: 90 minutes is 1 hour and 30 minutes.

Common Mistakes

  • Mistake: Students often forget to convert hours to minutes when calculating durations.

    Correction: Always convert both times to the same unit (either hours or minutes) before subtracting.

  • Mistake: Students may subtract incorrectly when the end time is earlier than the start time.

    Correction: If the end time is earlier, add 24 hours to the end time before subtracting.

← Back Start Practice