PPT: Time & Temperature | Mathematics for Class 5 PDF Download

 Page 1


What's the time?
Page 2


What's the time?
24-HOURS TIME CLOCK
Generally we use a 12-hours clock to measure time.
 Some departments like railways, airlines and armed forces use the 24-
hours time clock.
Digital watch also show time in 24-hours clock time. Instead of using
a.m. or p.m.,
24 hours from midnight to the next midnight are numbered from 0 to 24.
In a 24-hours time clock the time in hours is expressed using 4-digit
numerals.
Page 3


What's the time?
24-HOURS TIME CLOCK
Generally we use a 12-hours clock to measure time.
 Some departments like railways, airlines and armed forces use the 24-
hours time clock.
Digital watch also show time in 24-hours clock time. Instead of using
a.m. or p.m.,
24 hours from midnight to the next midnight are numbered from 0 to 24.
In a 24-hours time clock the time in hours is expressed using 4-digit
numerals.
12 hrs to 24 hrs 
Page 4


What's the time?
24-HOURS TIME CLOCK
Generally we use a 12-hours clock to measure time.
 Some departments like railways, airlines and armed forces use the 24-
hours time clock.
Digital watch also show time in 24-hours clock time. Instead of using
a.m. or p.m.,
24 hours from midnight to the next midnight are numbered from 0 to 24.
In a 24-hours time clock the time in hours is expressed using 4-digit
numerals.
12 hrs to 24 hrs 
Conversion of Time
Conversion of 24-hours time clock to 12-hours time clock
Rule 1 : For the time from midnight (0000 hours) to 12 noon
(1200 hours), if the number formed by the first two digits from
the left of the 24-hour clock time is less than 12, it denotes the
number of hours before noon. So, a.m. is used.
Page 5


What's the time?
24-HOURS TIME CLOCK
Generally we use a 12-hours clock to measure time.
 Some departments like railways, airlines and armed forces use the 24-
hours time clock.
Digital watch also show time in 24-hours clock time. Instead of using
a.m. or p.m.,
24 hours from midnight to the next midnight are numbered from 0 to 24.
In a 24-hours time clock the time in hours is expressed using 4-digit
numerals.
12 hrs to 24 hrs 
Conversion of Time
Conversion of 24-hours time clock to 12-hours time clock
Rule 1 : For the time from midnight (0000 hours) to 12 noon
(1200 hours), if the number formed by the first two digits from
the left of the 24-hour clock time is less than 12, it denotes the
number of hours before noon. So, a.m. is used.
Rule 2 : For the time from 1201 hours to 1259 hours, if the number
formed by the first two digits from the left of the 24-hours time
clock is 12 (other than 1200), then p.m. is used.
Rule 3 : 1200 hours denote 12 : 00 noon.
Rule 4 : For the time from noon to midnight, if the number
formed from the first two digits from the left of the 24-hours
time clock is 13 or more, then the difference between the
number and 12 gives the number of hours and p.m. is used
with it.