Timetables, phones and computers often use the 24-hour clock. Year 3 explorers change times between the 12-hour and 24-hour clock, use a.m. and p.m. correctly and add minutes across the hour.
What your child will learn
- Read 24-hour times such as 15:30 and 08:45
- Change 24-hour times to a.m. and p.m. times, and back
- Use a.m. and p.m. for times through the day
- Add minutes to a time, carrying into the next hour
The 24-hour clock
The 24-hour clock counts the hours from 00 at midnight to 23. Morning times look almost the same: 8:45 a.m. is 08:45. For afternoon and evening times, add 12 to the hour: 4:15 p.m. is 16:15. To go back, take 12 away: 19:00 is 7:00 p.m.
Why we use it
With 24 hours on the clock there is no need for a.m. or p.m., so there is no mix-up between 7 in the morning and 7 in the evening. That is why train, bus and flight timetables use it.
Example questions
Here are a few questions like the ones in the first quest. Can you solve them?
1. Ben eats dinner at 7:30. Is that a.m. or p.m.?
- a.m.
- p.m.
Show answer
Answer: p.m.. a.m. is from midnight to midday — the morning. p.m. is from midday to midnight — the afternoon, evening and night. Ben eats dinner in the evening, so it is 7:30 p.m.
2. Zara goes to sleep at 9:00. Is that a.m. or p.m.?
- a.m.
- p.m.
Show answer
Answer: p.m.. a.m. is from midnight to midday — the morning. p.m. is from midday to midnight — the afternoon, evening and night. Zara goes to sleep in the night, so it is 9:00 p.m.
3. Zara has recess at 10:00. Is that a.m. or p.m.?
- a.m.
- p.m.
Show answer
Answer: a.m.. a.m. is from midnight to midday — the morning. p.m. is from midday to midnight — the afternoon, evening and night. Zara has recess in the morning, so it is 10:00 a.m.
Tips for grown-ups
- Switch a phone or tablet to the 24-hour clock for a week and read it together.
- Look at a bus, train or flight timetable and find the afternoon departures.