TIME for grade 3 and other thing as well.ppt

time clock

1. 1

2. 2

3. 3
1 year = 365 days
1 year = 52 weeks
1 year = 12 months
1 week = 7 days
1 day = 24 hours
1 hour = 60 minutes
1 minute = 60 seconds

4. 4
a.m. or A.M. – an abbreviation
of ante meridiem (before noon)
p.m. or P.M. – an abbreviation
of post meridiem (after noon)

5. 5
International Date Line
an imaginary line through the
Pacific Ocean roughly along the
180
th
meridian, agreed upon as the
place where each new calendar
day begins. The calendar day to
the east of the line is one day
earlier than to the west.

6. 6
prime meridian – The zero
meridian (0°) used as a
reference line from which
longitude east and west is
measured. It passes through
Greenwich, England.

7. 7
Time Conversion
 Using a bridge map can help
organize your thinking when
converting from one time unit
to another.

8. 8
as
(just like)
Relating factor

9. 9
Example:
4 weeks = ______ days28
Think: 1 week = 7 days
4 x 7 = 28
1 week
7 days
4 weeks
___days28

10. 10
Example:
3 years = ______ months
3 x 12 = 36
36
Think: 1 year = 12 months
1 year
12 months
3 years
___ months36

11. 11
Example:
3 days 8 hours = ______ hours
3 x 24 = 72 + 8 = 80
80
Think: 1 day = 24 hours
1 day
24 hours
3 days 8 hours
___ hours80

12. 12
Example:
420 seconds = ______ minutes
420 ÷ 60 = 7
7
Think: 60 seconds = 1 minute
60 seconds
1 minute
420 seconds
___minutes7

13. 13
Example:
42 months = __ years __ months
Think: 12 months = 1 year
42 ÷ 12 = 3 r 6
3 6
12 months
1 year
42 months
__ years __months3 6

14. 14
Example:
100 hours = _____ days
Think: 24 hours = 1 day
100 ÷ 24 = 4 4/24 = 4 1/6
4 1/6
24 hours
1 day
100 hours
___ days4 1/6

15. 15
Time units can be added,
subtracted, multiplied or divided.
To add or subtract measures of time:
1. Add or subtract the seconds.
2. Add or subtract the minutes.
3. Add or subtract the hours.
Rename if necessary in each step.

16. 16
Find the sum.
15 h 23 min
+ 7 h 15 min
Add minutes
38 min
Add hours
22 h
Rename answer
if necessary

17. 17
Find the sum.
6 h 12 min
+ 1 h 55 min
Add minutes
67 min
Add hours
7 h
Rename answer
if necessary
= 8 h 7 min
67 min = 1 h 7 min

18. 18
Find the difference.
5 h 48 min
- 2 h 12 min
36 min
Subtract hours
3 h
Subtract minutes
Rename answer
if necessary

19. 19
Find the difference.
24 min
- 13 min 12 s
Subtract minutes
10 min
Subtract seconds
Rename answer
if necessary
23
60 s
48 s
510

20. 20
Ending Time
- Starting Time
Elapsed Time
To calculate elapsed time –
subtract the starting time from
the ending time of the event.
9:55 a.m.
- 6:35 a.m.
3 h 20 min

21. 21
10:50
- 7:30
Subtract minutes
20hr
Subtract hours
3
3 hours 20 minutes
Start time
Ending time
Marcy was babysitting from
7:30 p.m. to 10:50 p.m. How
long did Marcy baby-sit?
min

22. 22
Military time is based
on a 24 hour clock.
24
hour
clock
Hours from 1:00 a.m. to 12:00 p.m
are from 01:00 to 12:00
Hours from 1:00 p.m. to 12:00 a.m.
are from 13:00 to 24:00

23. 23
Add 12 hours to 1: 00 p.m.
to 12:00 a.m. to change from
standard time to military time.
Examples:
1:15 p.m. is13:15 military time
9:45 p.m. is21:45 military time
12:00 a.m. is24:00 military time
1:30 a.m. is01:30 military time

24. 24
11:30
- 6:50
40hr4
Susie worked from 6:50 a.m. to
11:30 a.m. on Monday. How
long did she work?
1090
Subtract hours
Subtract minutes
Rename 1 hour to minutes
4 hours 40 minutes
min

25. 25
8:25
- 1:45
40hr
John worked from 1:45 p.m. to
8:25 p.m. on Wednesday. How
long did he work?
785
Subtract hours
Subtract minutes
Rename 1 hour to minutes
6 hours 40 minutes
6 min

26. 26
6:00
- 10:30
30hr7
Think:
military
time
add 12
to hour
John worked from 10:30 a.m.
to 6:00 p.m. on Friday. How
long did he work?
Add 12 to hour
7 hours 30 minutes
18:00
1760
Rename 1 hour to minutes
Subtract hours
Subtract minutes
min

27. 27
Time units can be expressed
using fractions..
Quarter of an hour
Half an hour