Step-by-step Maths Level 5: Durations across an hour or a day change

Method. Count on in steps from the start to the arrival time: first to the next hour, then whole hours, then minutes.

1. Count the minutes to the next hour. Go from the start time to the next full hour.
   08:53 to 09:00 is 7 min
2. Count the whole hours. Count each full hour after that.
   1 whole hours
3. Count the minutes after the last whole hour. Count on to the arrival time.
   36 min
4. Add the parts. Add all the parts for the total time.
   7 min + 1 h + 36 min = 1 h 43 min
5. Write the answer. Give the journey time in hours and minutes.
   1 h 43 min

Check. Check: 1 h 43 min added to 08:53 gives 10:36.

Watch out. Do not subtract the times as if they were ordinary numbers. Count on across the hour.

Method. Count on in steps from the start to the arrival time: first to the next hour, then whole hours, then minutes.

1. Count the minutes to the next hour. Go from the start time to the next full hour.
   08:07 to 09:00 is 53 min
2. Count the whole hours. Count each full hour after that.
   1 whole hours
3. Count the minutes after the last whole hour. Count on to the arrival time.
   57 min
4. Add the parts. Add all the parts for the total time.
   53 min + 1 h + 57 min = 2 h 50 min
5. Write the answer. Give the journey time in hours and minutes.
   2 h 50 min

Check. Check: 2 h 50 min added to 08:07 gives 10:57.

Watch out. Do not subtract the times as if they were ordinary numbers. Count on across the hour.

Method. Count on in steps from the start to the arrival time: first to the next hour, then whole hours, then minutes.

1. Count the minutes to the next hour. Go from the start time to the next full hour.
   13:29 to 14:00 is 31 min
2. Count the whole hours. Count each full hour after that.
   3 whole hours
3. Count the minutes after the last whole hour. Count on to the arrival time.
   38 min
4. Add the parts. Add all the parts for the total time.
   31 min + 3 h + 38 min = 4 h 9 min
5. Write the answer. Give the journey time in hours and minutes.
   4 h 9 min

Check. Check: 4 h 9 min added to 13:29 gives 17:38.

Watch out. Do not subtract the times as if they were ordinary numbers. Count on across the hour.

Method. Count on in steps from the start to the arrival time: first to the next hour, then whole hours, then minutes.

1. Count the minutes to the next hour. Go from the start time to the next full hour.
   17:20 to 18:00 is 40 min
2. Count the whole hours. Count each full hour after that.
   2 whole hours
3. Count the minutes after the last whole hour. Count on to the arrival time.
   8 min
4. Add the parts. Add all the parts for the total time.
   40 min + 2 h + 8 min = 2 h 48 min
5. Write the answer. Give the journey time in hours and minutes.
   2 h 48 min

Check. Check: 2 h 48 min added to 17:20 gives 20:08.

Watch out. Do not subtract the times as if they were ordinary numbers. Count on across the hour.

Method. Count on in steps from the start to the arrival time: first to the next hour, then whole hours, then minutes.

1. Count the minutes to the next hour. Go from the start time to the next full hour.
   20:08 to 21:00 is 52 min
2. Count the whole hours. Count each full hour after that.
   2 whole hours
3. Count the minutes after the last whole hour. Count on to the arrival time.
   34 min
4. Add the parts. Add all the parts for the total time.
   52 min + 2 h + 34 min = 3 h 26 min
5. Write the answer. Give the journey time in hours and minutes.
   3 h 26 min

Check. Check: 3 h 26 min added to 20:08 gives 23:34.

Watch out. Do not subtract the times as if they were ordinary numbers. Count on across the hour.

Method. Count on in steps from the start to the arrival time: first to the next hour, then whole hours, then minutes.

1. Count the minutes to the next hour. Go from the start time to the next full hour.
   09:04 to 10:00 is 56 min
2. Count the whole hours. Count each full hour after that.
   1 whole hours
3. Count the minutes after the last whole hour. Count on to the arrival time.
   10 min
4. Add the parts. Add all the parts for the total time.
   56 min + 1 h + 10 min = 2 h 6 min
5. Write the answer. Give the journey time in hours and minutes.
   2 h 6 min

Check. Check: 2 h 6 min added to 09:04 gives 11:10.

Watch out. Do not subtract the times as if they were ordinary numbers. Count on across the hour.

Method. Count on in steps from the start to the arrival time: first to the next hour, then whole hours, then minutes.

1. Count the minutes to the next hour. Go from the start time to the next full hour.
   16:37 to 17:00 is 23 min
2. Count the whole hours. Count each full hour after that.
   2 whole hours
3. Count the minutes after the last whole hour. Count on to the arrival time.
   33 min
4. Add the parts. Add all the parts for the total time.
   23 min + 2 h + 33 min = 2 h 56 min
5. Write the answer. Give the journey time in hours and minutes.
   2 h 56 min

Check. Check: 2 h 56 min added to 16:37 gives 19:33.

Watch out. Do not subtract the times as if they were ordinary numbers. Count on across the hour.

Method. Count on in steps from the start to the arrival time: first to the next hour, then whole hours, then minutes.

1. Count the minutes to the next hour. Go from the start time to the next full hour.
   18:04 to 19:00 is 56 min
2. Count the whole hours. Count each full hour after that.
   0 whole hours
3. Count the minutes after the last whole hour. Count on to the arrival time.
   51 min
4. Add the parts. Add all the parts for the total time.
   56 min + 0 h + 51 min = 1 h 47 min
5. Write the answer. Give the journey time in hours and minutes.
   1 h 47 min

Check. Check: 1 h 47 min added to 18:04 gives 19:51.

Watch out. Do not subtract the times as if they were ordinary numbers. Count on across the hour.

Method. Count on in steps from the start to the arrival time: first to the next hour, then whole hours, then minutes.

1. Count the minutes to the next hour. Go from the start time to the next full hour.
   18:53 to 19:00 is 7 min
2. Count the whole hours. Count each full hour after that.
   4 whole hours
3. Count the minutes after the last whole hour. Count on to the arrival time.
   0 min
4. Add the parts. Add all the parts for the total time.
   7 min + 4 h + 0 min = 4 h 7 min
5. Write the answer. Give the journey time in hours and minutes.
   4 h 7 min

Check. Check: 4 h 7 min added to 18:53 gives 23:00.

Watch out. Do not subtract the times as if they were ordinary numbers. Count on across the hour.

Method. Count to midnight, then count on from midnight to the arrival time.

1. Count to midnight. Midnight is 24:00, the start of the next day.
   22:31 to 24:00 is 1 h 29 min
2. Count on from midnight. Add the time after midnight.
   00:00 to 02:14 is 2 h 14 min
3. Add the two parts. The journey crosses midnight, so we add the two parts.
   1 h 29 min + 2 h 14 min = 3 h 43 min
4. Write the answer. Give the journey time in hours and minutes.
   3 h 43 min

Check. Check: 3 h 43 min is the same as 223 minutes.

Watch out. When a journey crosses midnight, the arrival time is smaller than the start time. Count across the day change.

Method. Count on in steps from the start to the arrival time: first to the next hour, then whole hours, then minutes.

1. Count the minutes to the next hour. Go from the start time to the next full hour.
   19:02 to 20:00 is 58 min
2. Count the whole hours. Count each full hour after that.
   0 whole hours
3. Count the minutes after the last whole hour. Count on to the arrival time.
   56 min
4. Add the parts. Add all the parts for the total time.
   58 min + 0 h + 56 min = 1 h 54 min
5. Write the answer. Give the journey time in hours and minutes.
   1 h 54 min

Check. Check: 1 h 54 min added to 19:02 gives 20:56.

Watch out. Do not subtract the times as if they were ordinary numbers. Count on across the hour.

Method. Count on in steps from the start to the arrival time: first to the next hour, then whole hours, then minutes.

1. Count the minutes to the next hour. Go from the start time to the next full hour.
   15:31 to 16:00 is 29 min
2. Count the whole hours. Count each full hour after that.
   0 whole hours
3. Count the minutes after the last whole hour. Count on to the arrival time.
   23 min
4. Add the parts. Add all the parts for the total time.
   29 min + 0 h + 23 min = 52 min
5. Write the answer. Give the journey time in hours and minutes.
   52 min

Check. Check: 52 min added to 15:31 gives 16:23.

Watch out. Do not subtract the times as if they were ordinary numbers. Count on across the hour.

Method. Count on in steps from the start to the arrival time: first to the next hour, then whole hours, then minutes.

1. Count the minutes to the next hour. Go from the start time to the next full hour.
   17:35 to 18:00 is 25 min
2. Count the whole hours. Count each full hour after that.
   1 whole hours
3. Count the minutes after the last whole hour. Count on to the arrival time.
   24 min
4. Add the parts. Add all the parts for the total time.
   25 min + 1 h + 24 min = 1 h 49 min
5. Write the answer. Give the journey time in hours and minutes.
   1 h 49 min

Check. Check: 1 h 49 min added to 17:35 gives 19:24.

Watch out. Do not subtract the times as if they were ordinary numbers. Count on across the hour.

Method. Count to midnight, then count on from midnight to the arrival time.

1. Count to midnight. Midnight is 24:00, the start of the next day.
   23:35 to 24:00 is 25 min
2. Count on from midnight. Add the time after midnight.
   00:00 to 01:40 is 1 h 40 min
3. Add the two parts. The journey crosses midnight, so we add the two parts.
   25 min + 1 h 40 min = 2 h 5 min
4. Write the answer. Give the journey time in hours and minutes.
   2 h 5 min

Check. Check: 2 h 5 min is the same as 125 minutes.

Watch out. When a journey crosses midnight, the arrival time is smaller than the start time. Count across the day change.

Method. Count to midnight, then count on from midnight to the arrival time.

1. Count to midnight. Midnight is 24:00, the start of the next day.
   22:52 to 24:00 is 1 h 8 min
2. Count on from midnight. Add the time after midnight.
   00:00 to 01:55 is 1 h 55 min
3. Add the two parts. The journey crosses midnight, so we add the two parts.
   1 h 8 min + 1 h 55 min = 3 h 3 min
4. Write the answer. Give the journey time in hours and minutes.
   3 h 3 min

Check. Check: 3 h 3 min is the same as 183 minutes.

Watch out. When a journey crosses midnight, the arrival time is smaller than the start time. Count across the day change.

Method. Count on in steps from the start to the arrival time: first to the next hour, then whole hours, then minutes.

1. Count the minutes to the next hour. Go from the start time to the next full hour.
   18:16 to 19:00 is 44 min
2. Count the whole hours. Count each full hour after that.
   3 whole hours
3. Count the minutes after the last whole hour. Count on to the arrival time.
   53 min
4. Add the parts. Add all the parts for the total time.
   44 min + 3 h + 53 min = 4 h 37 min
5. Write the answer. Give the journey time in hours and minutes.
   4 h 37 min

Check. Check: 4 h 37 min added to 18:16 gives 22:53.

Watch out. Do not subtract the times as if they were ordinary numbers. Count on across the hour.