STD 8 MATHEMATICS LESSON. TERM 2 2020.

TOPIC –TIME

   A  day  has  24 hrs

• Time can be given in
• 12 hour clock system.
• 24 hour clock system.

To convert a.m into 24 hr clock time

NB-the answer must be in 4 digits.

Eg a)3.20 am---------0320 hrs

-this means 3 hrs 20 min after midnight.

b)3 am-----------0300 hrs

-this means 3 hrs  after midnight.

11. C) 11.20 am------------1120 hrs

-this  means 11 hrs 20 mins  after  midnight.

d)12.20 am ------------0020 hrs

-this means 20 mins  after midnight.T               

TO CONVERT  PM   INTO   24 HR  CLOCK.

NB-add  12  hours e.g

a)3.45 pm

3. 45

        +   12. 00

              15.45      =   1545 hrs

1545 hrs means 15 hours and   45  minutes after midnight.

NB-Midnight is shown by 4 zeroes. i.e     0000 hrs.

To convert 24 hr clock time to am  e.g

a)0705 h-------------7.05 am(omit the  first zero)

b)1030 h- 10.30 am  

c)1125 h---11.25 am

To  convert  24 h  clock time into pm

  -The easiest way to  recognize  them (apart from 12) is to look for those Numbers from 13 to 23

   E.g. 1730 h

 -subtract 1200 hours.

           1 7   3 0

    _     1 2   0 0

               5   3 0

=      5.30 p.m

QUESTIONS

CONVERT THE FOLLOWING am/pm into 24 clock time.

1. 4 am 

2)4.20 am

3)11.30pm

4) 3.20pm

5)12 midnight

6)2200h

7)  0440h

8) 0045 h

9) 1345h

10)0805h