Time
Calculating time intervals
A time interval is the amount of time that passes between two times. A time line helps you count it in steps.
How to work it out
1. Count on from the start time to the next whole hour. 2. Count the whole hours after that. 3. Count the extra minutes to the end time. 4. Add all the parts together.
Worked examples
Within the same hour
- A train leaves at 10:11 and arrives at 10:47.
- From 11 minutes to 47 minutes is 47 − 11 = 36.
Answer: The journey takes 36 minutes.
Across whole hours
- It is 5:37 p.m. and a concert starts at 7:15 p.m.
- 5:37 → 6:00 is 23 minutes; 6:00 → 7:00 is 1 hour; 7:00 → 7:15 is 15 minutes.
- 23 min + 1 hour + 15 min = 1 hour 38 minutes.
Answer: You wait 1 hour 38 minutes (98 minutes).
Where you see this in real life
- Working out how long a train or bus journey takes from a timetable.
- Finding how long you must wait for the next train.
- Comparing race times to see who was fastest.
Key words
- Time interval
- The amount of time that passes between two times.
- Timetable
- A table of times showing when things happen.
- Minute
- A unit of time equal to 60 seconds.