time introduction to 24 hour time

24 Hour Time

Learn which

of these

numbers are

telling you

about time !

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12 hour time

24 hour time

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24 Hour time ‘names’ each hour.

Two important things to know about 24 hour time……

• 24 hour time uses numbers only to show the time.

• 24 hour time does not use am or pm.

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• Defence forces

Who would use 24 hr time ?

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Unit 4 – report ETA at base camp

ETA at base camp is 14:30 hours

ETA means Estimated Time of Arrival

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Transport companies

Who would use 24 hr time ?

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Discuss these ideas with your teacher,

• write some sentences about how 24 hour is different from 12 hour time.

• write a sentence about where24 hour time is used.

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then in your exercise book:

Communicating and understanding

• Look at the two next slides and talk about what has happened…..

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The tide is good for fishing at 7 o’clock tomorrow.

I’ll pack a torch !

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The tide is good for fishing at 0700 tomorrow.

Great- early in the day is the best time !

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Using 24 Hour time stops confusion !

Look back at the slides showing who uses 24 hour time….

Discuss: Why is that the best way of communicating time for them ?

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Where do you see 24 hr time ?

Tide times in the newspaper.

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Tide times

Think about how the tides go in and out all day every day, never stopping. The times for high tides and low tides change everyday.

Lots of people plan to go fishing at the best times – the best times are at the change of the tide. The change of tides can happen during the day or during the night.

Question Why do you think it is a good idea to have the times written in 24 hour time ?

Answer Using 24 hour time is a good way to show the tide times because ….

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Travel timetables – eg buses, planes, trains

Where do you see 24 hr time ?

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Think: Which circle of numbers shows 12 hour time ?

Do you understand why there are two different numbers around the outside of the circle ?

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12 hour time 24 Hour time

2 am

2 pm

11 am

11 pm

Use the clock face to convert the following times:

24 hour time 12 Hour time

0900

2100

0400

1600

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Language of time

• 12 hour time / 24 hour time• digital• analog• timetable / calendar• (middle) midnight / midday = noon• am = first 12 hours of the day• pm = next 12 hours of the day• h = hours• min = minutes• notation = way of writing something down –

the writing ‘style’ you use• convert / conversion = change

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