Time
UNITS OF TIME
We can measure time in:
Seconds (sec)
Minutes (min)
Hours (hr)
Days
If we need to change between one unit of time and another we need to
know:
1 minute = 60 seconds
1 hour = 60 minutes
1 day = 24 hours
To Change From Minutes And Seconds To Seconds
1 minute
=
60 seconds
2 minutes
=
2 x 60 seconds =
120 seconds
5 minutes
=
5 x 60 secs
300 secs
1 min 5 secs
=
60 secs + 5 secs
2 min 30 secs
=
=
2 x 60 secs + 30 secs
120 secs + 30 secs = 150 secs
so
So
(i)
then (ii)
=
= 65 secs
multiply the minutes by 60
add on any extra seconds
f lex i p
Make sure you understand the examples then have a go at changing
the following.
ac k s
1
Time
A)
Change these into seconds
1)
3 minutes
= ............. seconds
2)
4 mins
= ............. secs
3)
10 mins
= ............. secs
4)
1 min 12 secs
= ............. secs
5)
2 mins 24 secs = ............. secs
6)
1 min 35 secs = ............. secs
To Change From Seconds To Minutes And Seconds
60 secs = 1 minute
120secs = 120  60
= 2 mins
420 secs = 420  60
= 7 mins
65 secs is 65  60
= 1 min remainder 5 secs
= 1 min 5 secs
128 secs is 128  60
= 2 mins rem 8 secs
= 2 mins 8 secs
So
(i) divide by 60 to find how many whole minutes
then
(ii) add on the remaining seconds.
Make sure you understand then have a go at changing these:
f lex i p
B)
1)
120 secs
=
.................. minutes
2)
84 secs
=
.................. mins ...............
secs
3)
75 secs
=
.................. mins ...............
secs
4)
67 secs
=
.................. mins ...............
secs
5)
96 secs
=
.................. mins ...............
secs
6)
142 secs
=
.................. mins ...............
secs
ac k s
2
Time
Changing Between Hour And Minutes And Minutes
This is very similar to changing between seconds and minutes because
there are:
60 mins in 1 hour.
eg.
eg.
Change to minutes
4 hours
=
4 x 60 = 240 mins
2 hrs 15 mins
=
2 x 60 mins + 15 mins
=
120 + 15 = 135 mins
300 mins is 300  60
=
5 hours
78 mins is 78  60
=
1 hr remainder 18 mins
Change to hours
Make sure you understand, then have a go at changing these times:
f lex i p
C)
1)
6 hours =
2)
8 hrs =
................ mins
3)
1 hr 17 mins =
................ mins
4)
1 hr 25 mins =
................ mins
5) 2 hrs 38 mins =
................ mins
6)
180 mins =
................ hrs
7)
72 mins =
................ hr
............... mins
8)
84 mins =
................ hr
............... mins
9)
98 mins =
................ hr
............... mins
10)
150 mins =
................ hr
............... mins
ac k s
................ minutes
3
Time
Changing Between Hours And Days
To change between hours and days we need to know:
1 day = 24 hours
so
2 days = 2 x 24 = 48 hours
1 day 4 hrs = 1 x 24 hours + 4 hrs = 28 hrs
and
36 hours is 36  24 = 1 day rem 12 hours
27 hours is 27  24 = 1 day 3 hours
Make sure you understand the examples then have a go at changing
these times:
D)
1)
3 days =
................ hrs
2)
10 days =
................ hrs
3)
1 day 8 hrs =
................ hrs
4)
1 day 13 hrs =
................ hrs
5) 2 days 22 hrs =
................ hrs
6)
60 hrs =
................ days ............... hrs
7)
48 hrs =
................ days ............... hrs
8)
26 hrs =
................ days ............... hrs
9)
30 hrs =
................ days ............... hrs
10)
64 hrs =
................ days ............... hrs
f lex i p
Check your answers, then discuss with your tutor what you need to
work on next.
ac k s
4
Time
Answers
Units Of Time
A)
B)
C)
1) 180 secs
2) 240 secs
3) 600 secs
4) 72 secs
5) 144 secs
6) 95 secs
1) 2 mins
2) 1 min 24 secs
3) 1 min 15 secs
4) 1 min 7 secs
5) 1 min 36 secs
60 2 min 22 secs
1) 360 mins
2) 480 mins
3) 77 mins
4) 85 mins
5) 158 mins
6) 3 hrs
7) 1 hr 12 mins
8) 1 hr 24 mins
9) 1 hr 38 mins
1) 72 hrs
2) 240 hrs
3) 32 hrs
4) 37 hrs
5) 70 hrs
6) 2 days 12 hrs
7) 2 days
8) 1 day 2 hrs
9) 1 day 6 hrs
10) 2 hrs 30 mins
D)
f lex i p
10) 2 days 16 hrs
ac k s
5