Time
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Calculating times is an important area in the SATS and the ability to calculate time is something that we need everyday.
Here is some information you must know.
| 60 seconds | =1 minute |
| 60 minutes | =1 hour |
| 24 hours | =1 day |
| 365 days | = 1 year. This is only approximate: there is a quarter day every year, but it is counted every four years (see below) |
| 366 days | = leap year (every four years) |
Time can be shown in either the 24 hour system or the 12 hour system.
24 hour clock.
The 24 hour clock is often used when travelling to ensure that there is no confusion between morning and afternoon.
The 24 hour clock system is often used on digital clocks (clocks without a clock face).
All times before twelve midday are shown as normal. All times after midday you add 12 hours on.
So to convert to the 24 hour system from the am/pm system, add 12 hours.
To convert from the 24 hour system to am/pm, subtract 12 hours.
So for example:
1 am or 1 O'clock in the morning is 1 oclock.
1 pm or 1 O'clock in the afternoon is 13.00 hours (1 + 12)
14:45 hours or 2.45 in the afternoon is 2.45 pm( 14 - 12)
Note that the minutes stay the same.
Here is a table with a mixture of 12 and 24 hour systems .Can you convert between the two?
Just remember the rules.
To convert to the 24 hour system from the am/pm system add 12 hours.
To convert from the 24 hour system to am/pm subtract 12 hours.
See if you can convert the following:
(a) 240 seconds into minutes
(b) 3 hours into minutes
(c) 3 days into hours
(d) 720 minutes into hours
Answers
(a) 240 seconds into minutes 4 minutes
(b) 3 hours into minutes 180 minutes
(c) 3 days into hours 72 hours
(d) 720 minutes into hours 12 hours
That wasn't too bad was it?
To finish off, find the difference between the times in the table. This will be very useful for the SATS.
Good luck!
SATS example
I start a journey at 9.15 am and finish the journey at 12.10 pm how long did I travel for?
Answer
9.15 am till 12 15am is 3 hours, however our journey finished 5 minutes less than 3 hours
So our journey lasted for 2 hours and 55 minutes (60 minutes in an hour).
Well we have run out of time!
I hope you feel more confident with time now.
Good luck!
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Note, if you are a teacher and
you want more FREE Maths resources you can visit |