Comparing Time Durations
Compare durations of events and calculate the time taken by particular events or tasks
What a learner can do afterwards
- Calculate how long an activity lasted given start and end times
- Compare the duration of two events and identify which was longer
- Solve a problem such as 'The lesson starts at 10:15 and ends at 11:00. How long is it?'
The lesson
Duration means how much time something takes. To find a duration, look at the start time and the end time. Then count what happened in between. You already know how to read a clock and use minutes and hours, so this just puts that to work.
The lesson ends at 11:00. Count on from 10:15: first to 10:45 is 30 minutes, then to 11:00 is 15 more minutes. Add them together: 30 plus 15 is 45 minutes. The lesson lasted 45 minutes.
When you compare two events, the one with more minutes is the longer one. If the time crosses into a new hour, count up to the new hour first, then add what is left. Remember that 1 hour equals 60 minutes, so 60 minutes always beats a smaller number.
To find a duration, count from the start time to the end time. To compare durations, more minutes means longer.
Watch it
Where it sits
This opens up
Where this leads
8 questions wait behind this lesson, each with its answer explained. Every answer feeds the sky: stars light as they are learned, and dim when it is time to come back.