12-hour and 24-hour clocks

Mathematics · Measurement · ages 8-9

Name ______________________ Date ____________

Afternoon times add 12 to the hour. 3:45 pm becomes quarter to four in 24 hour time. What is its hour number?
Answer: ______________
What is 3:45 pm in 24 hour time?
- 03:45
- 15:45
- 13:45
- 14:45
Which of these times is written in 24-hour format?
- 3:45 pm
- 15:45
- Quarter past three
07:00 and 7:00 am are the same time.
Circle one: True False
Convert 7:30 pm to 24 hour time. What is the hour number?
Answer: ______________
Malik's football match starts at 14:20 in 24-hour time. What hour number does that become in 12-hour time? Type just the hour.
Answer: ______________
What is 19:30 in 12 hour time?
- 7:30 am
- 9:30 pm
- 7:30 pm
- 19:30 am
A matching game pairs 8:05 am with 08:05 and 8:05 pm with 20:05. Sam says morning stays small and evening adds 12. Is Sam right?
Circle one: True False
Priya says 20:15 in 12-hour time is 10:15 pm. Is she right?
- Yes, that's correct
- No, it's 8:15 pm
- No, it's 9:15 pm
11:55 pm in 24 hour time: 11 + 12 = ?
Answer: ______________

Answer key

For grown-ups. Fold this page away before handing over the rest.

15 · The hour is 15 because 3 + 12 = 15.
15:45 · 15:45 is correct because afternoon hours add 12: 3 + 12 = 15, with 45 minutes unchanged.
15:45 · 24-hour time uses numbers only, like 15:45, and never am or pm.
True · Morning times before noon look almost the same in both clocks.
19 · The hour is 19 because 7 + 12 = 19.
2 · Subtract 12 from 14 to get 2. The match starts at 2:20 pm.
7:30 pm · 7:30 pm is correct because 19 - 12 = 7 and hours over 12 are pm.
True · Sam is right because 8:05 am is 08:05 and 8 + 12 = 20 gives 20:05 for the evening.
No, it's 8:15 pm · Subtract 12 from 20: 20 - 12 = 8. The time is 8:15 pm, not 10:15 pm.
23 · 23 is the hour because 11 + 12 = 23.