Question

1. change these times to the 24hr clock a) 2:30 b) 1:15

2. change these times to the 12hr clock c) 04:05 d) 15:25

Answer 1

To change 12hr times to the 24hr clock:

• if the time is am add a leading zero
• if the time is pm add 12 hours

To change 24hr times to the 12hr clock:

• if the time is less than 12:00 then it is am (simply delete the leading zero)
• if the time is more than 12:00, then it is pm - subtract 12 hours

1. a) 2:30 + 12 = 14:30 OR 02:30 (depending if 2:30 is pm or am)

b) 1:15 + 12 = 13:15 OR 01:15 (depending if 1:15 is pm or am)

2. c) 04:05 = 4:05 am

d) 15:25 - 12:00 = 3:25 pm