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P4 Maths: 24-Hour Time Calculations (Paper 3 (challenge))
Tutor Prep Guide · am/pm and 24-hour conversion; durations across noon and midnight; minute carrying; everyday timetables
P4 Maths: 24-Hour Time Calculations (Paper 3 (challenge))
Paper 3 (challenge): ten time questions on am/pm and 24-hour conversion, durations across noon and midnight, and minute carrying, with answers and one-line notes.
Direct answers Level: P4 maths; format: am/pm and 24-hour conversion, durations, spans across midnight, and minute carrying or borrowing.
01 Paper details (check answers afterwards)
| Item | Detail |
|---|---|
| Questions | 10 |
| Suggested time | 20 |
| Difficulty mix | Foundation 3 · Intermediate 3 · Challenge 3 · Error redo 1 |
| Chapter | Chapter: P4 Maths: 24-Hour Time Calculations |
| Level | P4 |
02 Questions (10 items)
- FoundationHow long is it from 23:50 to 01:35 the next day?
- FoundationA journey takes 3 hours 50 minutes and starts at 09:40. When does it end?
- FoundationA coach leaves every 1 hour 20 minutes from 06:15. When does the fourth coach leave?
- IntermediateHow is 16:48 written in 12-hour time?
- IntermediateA library opens 9:00 am to 12:00 noon and 2:00 pm to 5:30 pm. How long is it open in a day?
- IntermediateEach trip takes 45 minutes and there are 12 trips a day. What is the total driving time?
- ChallengeWhat time is 4 hours 50 minutes after 20:35?
- ChallengeAn activity runs from 10:20 to 15:05 with a 40-minute break. How long is the activity itself?
- ChallengeWhat time is 90 minutes after 21:15?
- Error redoA pupil says 00:30 in 24-hour time is 12:30 pm. What is wrong?
03 Answers and one-line notes
| # | Answer | One-line note |
|---|---|---|
| 1 | 1 hours 45 minutes. | Ten minutes take it to 00:00, then add 1 hour 35 minutes to get 105 minutes, or 1 hour 45 minutes. |
| 2 | 13:30. | 09:40 plus 3 hours is 12:40, and adding 50 minutes gives 13:30. |
| 3 | 10:15. | Each gap is 80 minutes, so three gaps make 240 minutes, or 4 hours; 06:15 plus 4 hours is 10:15. |
| 4 | 4:48 pm. | Subtract 12 from 16 to get 4, and keep the minutes, so it is 4:48 pm. |
| 5 | 6 hours 30 minutes. | Three hours in the morning plus 3 hours 30 minutes in the afternoon gives 6 hours 30 minutes. |
| 6 | 9 hours. | 45 x 12 = 540 minutes, which is 9 hours. |
| 7 | 01:25 the next day. | 20:35 plus 4 hours is 00:35, and adding 50 minutes gives 01:25 the next day. |
| 8 | 4 hours 5 minutes. | The whole span is 4 hours 45 minutes; taking away the 40-minute break leaves 4 hours 5 minutes. |
| 9 | 22:45. | 90 minutes is 1 hour 30 minutes, so adding it to 21:15 gives 22:45. |
| 10 | The direction is wrong: 00:30 is 12:30 am, just after midnight. | Any time starting 00: belongs to the small hours that begin a new day, never the afternoon. |
04 What to do after marking
- After marking, redo only the wrong items and write down which step went wrong (formula, unit, or misread number).
- Repeat the same item two days later; move to the next paper only when both attempts are correct.
- Parents only need the answer and note columns; there is no need to explain every item.
Check the answers; for a wrong duration, write both times down and subtract them in steps.Tutor Registration →
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