intermediate 1

Intermediate 1 Unit 2 Outcome 2

Speed Distance Time

8 Lessons

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Speed Distance TimeConvert from am/pm to 24 hours and vice versa

Revision of time

Revise previous work on time By the end of this lesson you will

1. Convert 12hr to 24hr clock

2. Convert 24 hr to 12hr clock

3. Count Method to find time intervals

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There are two major ways to show the time: "AM/PM" or "24 Hour Clock".

With the 24 Hour Clock the time is shown as how many hours and minutes since midnight.

AM/PM the day is split into the 12 Hours running from Midnight to Noon

(the AM hours)

the other 12 Hours running from Noon to Midnight (the PM hours).

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What Day is Midnight?What Day is Midnight?Midnight has another problem - there is nothing to Midnight has another problem - there is nothing to tell you "is this the beginning or ending of the day".tell you "is this the beginning or ending of the day".

Imagine you are told your friends are leaving on Imagine you are told your friends are leaving on holiday at "midnight" on 12th March, what day holiday at "midnight" on 12th March, what day

should you arrive to say goodbye?should you arrive to say goodbye?Do you get there on the 11th (assuming they leave Do you get there on the 11th (assuming they leave at the very start of the 12th), or the 12th (assuming at the very start of the 12th), or the 12th (assuming

they leave at the end of the 12th)?they leave at the end of the 12th)? It is better to use:It is better to use:

11:59 PM or 12:01 AM, or 11:59 PM or 12:01 AM, or 23:59 or 0:01 (24-Hour Clock) 23:59 or 0:01 (24-Hour Clock)

which the railroads, airlines and military actually dowhich the railroads, airlines and military actually doS

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2300220021002000190

018001700160015001400

1300

1200

11 pm

10 pm

9 pm8 pm7

pm6 pm5 pm4 pm3 pm2 pm

1 pm

midday

1100100009000800070

006000500040003000200

0100

0000

11 am

10 am

9 am8 am7 am6 am5am4 am3 am2 am1

ammidnigh

t

12/24 Hour Clock

To go from 12 hour clock to 24 hour clock just add 12 to the pm hours:Examples 9 pm

becomes11 pm

becomes5:30 pm becomes 10:30 pm

becomes

3:40 pm becomes 1:10 pm becomes15 40

17 30

21 00

23 00

22 30

13 10


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To go from 12 hour clock to 24 hour clock just add 12 to the pm hours:

Example 1 2.30 am 0230 Example 2 6.30 pm 1830

Add 12 to the pm hours

No ‘am’ or ‘pm’ in the answer

a) 4 pm

b) 6.15 pm

c) 7 am

d) 8.45 am

e) 10.30 pm

j) 12.15 pm

k) 1.11 am

l) 7 am

m) 11.45 am

n) 9.30 pm

f) Midday

g) 1.10 pm

h) 11.55 am

i) 10.05 pm

0) 10.05 am

p) 4.20 am

q) 3.35 pm

r) 9. 45 pm

1600

1815

0700

0845

2230

1200

1310

1155

2205

2415

0111

0700

1145

2130

1005

0420

1535

2145

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2300220021002000190

018001700160015001400

1300

1200

11 pm

10 pm

9 pm8 pm7

pm6 pm5 pm4 pm3 pm2 pm

1 pm

midday

1100100009000800070

006000500040003000200

0100

0000

11 am

10 am

9 am8 am7 am6 am5am4 am3 am2 am1

ammidnigh

t

12/24 Hour Clock

11 17pm

3 30 pm

6 pm 1 pm

2 09 am

4 50pm

To go from 24 hour clock to 12 hour clock just subtract 12 from the hours if it is greater than 12:

Examples

18 00 becomes

13 00 becomes

15 30 becomes 02 09 becomes

23 17 becomes 16 50 becomes


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To go from 12 hour clock to 24 hour clock just add 12 to the pm hours:

Example 1 0315 3.15 am Example 2 2010 8 10 pm

Any time after 1200 is pm

time

‘am’ or ‘pm’ must be in the

answer

a) 0230

b) 0805

c) 1640

d) 0245

e) 1805

j) 1020

k) 1430

l) 2240

m) 1935

n) 1800

f) 1200

g) 0545

h) 2315

i) 0020

0) 0925

p) 1425

q) 1955

r) 0635

2 30 am

8 05 am

4 40 pm

2 45 am

6 05 pm

Midday

5 45 am

11 15 pm

12 20 am

10 20 am

2 30 pm

10 40 pm

7 35 pm

10 20 am

9 25 am

2 25 pm

7 55 pm

6 35 am

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What do you

see?

intermediate 1

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