📏 Time
A day has 24 hours; a.m
▶ Play Door 13Reading Time, a.m./p.m. & 24-Hour Clock
A day has 24 hours. We split it into a.m. (midnight to noon) and p.m. (noon to midnight).
The 24-hour clock counts straight through: 1 p.m. is 13:00, 2 p.m. is 14:00, and so on (add 12 to afternoon/evening times).
On a normal clock, the short hand shows the hour and the long hand the minutes (each number = 5 minutes).
Worked example
Problem: Write 3 p.m. in 24-hour time.
- 3 + 12 = 15:00.
Answer: 3 + 12 = 15:00.
Elapsed Time & the Calendar
Elapsed time is how long something lasts — count forward from the start to the end.
Calendar facts: 7 days in a week, 12 months in a year, 365 days in a year (366 in a leap year). 1 hour = 60 min; 1 minute = 60 seconds.
Worked example
Problem: A class starts at 9:00 and ends at 11:30. How long is it?
- 9:00 → 11:00 is 2 hours, + 30 min = 2 hours 30 minutes.
Answer: 9:00 → 11:00 is 2 hours, + 30 min = 2 hours 30 minutes.