This document provides instruction on understanding 24-hour time. It explains that 24-hour time uses hours and minutes since midnight without AM/PM. The document shows how to convert between 12- and 24-hour times using tables and examples. Students are asked to complete a time conversion practice and solve a missing information problem from an airline timetable using the skills learned.

1. UNDERSTANDING 24 HOUR TIME
Class 5F

2. WELCOME EVERYONE
Do you know what “24- hour time” means?
Today, you will navigate this presentation and you will learn to:
• Convert 12- and 24- hour time systems.
• Identify time differences between 12- and 24- hour systems.
• Provide a written explanation of the different time systems. (Optional).
I am here to help you as always,
Mrs Fink.
Dreamstime, n.d. [Image file].

3. HARRY RECEIVES A TEXT
FROM HIS MUM:
“15:10?” He wonders.
“What does that mean?”
Fink, 2013a. [Image file].

4. THERE ARE 24 HOURS IN
A DAY…

5. 24 HOUR TIME SHOWS THE HOURS & MINUTES SINCE MIDNIGHT
A “24 hour clock” identifies the time
without the use of AM/PM information
that is used in a “12 hour clock”.
(e.g.: 11:00am = 11:00).
Kahlai, 2011. [Image file].
24 hour time is useful in military, travel and medical industries to avoid confusion.

6. CONVERTING 12- & 24- HOUR TIMES
LOOK AT THE TABLE →
To convert 12- hour to 24- hour time:
•
If “AM” time – do nothing, simply ensure four digits are used.
(e.g. 6:00am = 06:00).
•
If “PM” time - add “12”.
(e.g. 2:00pm = 2 + 12 = 14:00).
To convert 24- hour to 12- hour time:
•
FoundationsA, n.d. [Image file].
If time > 12, subtract 12 and note as “PM”.
(e.g. 15:00 (greater than 12) = 15 – 12 = 3:00pm).
•
If time < 12, do nothing, simply ensure four digits are used.
(e.g. 9:30am = 09:30).
*PRINT THIS PAGE

7. UNDERSTANDING 24- HOUR TIME
• Watch the video →
• Upon completion, return to this
presentation for next steps.
FutureSchoolVideos. 2011. [Video file.]
SOLA Optical, n.d. [Image file.]

8. TIME TO PRACTICE
• Time to practice!
• Instructions:
• Complete the practice questions →
• Take your time & use your printed
page to guide you when necessary.
• Upon completion, “print screen”
(results) and email to Mrs Fink before
returning to this presentation.
(http://www.outlook.com).
More Than a Sunday Faith, 2013. [Image file].
Mathopolis. (2013). [Web quiz].

9. YOUR TASK
• An airline timetable is missing key information!
• Using what you have learned today, calculate the missing pieces of information.
• Use Word, Excel or PowerPoint to present your findings. Present all times in 12 and 24
hour time.
• Email to Mrs Fink. http://www.outlook.com
• The next two slides have the information you need for the task!

10. FLIGHT TIMETABLE – FILL IN THE MISSING PIECES!
Flight #1:
Flight #3:
• Departure time: 11:00
• Departure time: 23:45
• Flight duration: 3.5 hours
• Flight duration: 0.75 hours
• Arrival time: _____
• Arrival time: ______
Flight #2:
Flight #4:
• Departure time: 15:15
• Departure time: 22:45
• Flight duration: 2.25 hours
• Flight duration: ______
• Arrival time: ______
• Arrival time: 00:15 (the next day)

11. FLIGHT TIMETABLE – FILL IN THE MISSING PIECES!
Flight #5:
• Departure time: _____
• Flight duration: 2.5 hours
• Arrival time: 13:30
Flight #7:
• Departure time: 10:45
• Flight duration: ______
• Arrival time: 12:30
Flight #6:
• Departure time: ______
• Flight duration: 1 hour 15 minutes
• Arrival time: 16:00
Flight #8:
• Departure time: ______
• Flight duration: 2 hours 30 minutes
• Arrival time: 19:15

12. IF YOU HAVE TIME…
• Harry is confused. How would you
explain 24- hour time to him?
• Write a short paragraph and email
to Mrs Fink. http://www.outlook.com
Fink, 2013b. [Image file].

13. WELL DONE!

14. REFERENCES (RESOURCE)
Australian Curriculum and Assessment Reporting Authority. (n.d.). Mathematics. Retrieved 21 December 2013, from
http://www.australiancurriculum.edu.au/Mathematics/Curriculum/F-10#level2
Dreamstime. (n.d.). Stock images: Happy smiley cartoon face. [Image file]. Retrieved 29 December 2013, from http://www.dreamstime.com/stock-imageshappy-cartoon-smiley-face-image2268974
Fink, V. (2013a). iPhone message. [Image file]. Received via email, 24 December, 2013.
Fink, V. (2013b). iPhone message. [Image file]. Received via email, 24 December, 2013.
FoundationsA. (n.d.). Lecon 4. [Image file]. Retrieved 24 December 2013, from
http://foundationsa.wikispaces.com/Lecon+4
FutureSchoolVideos. (2011). 24 hour time. [Video file]. Retrieved 26 December 2013, from http://www.youtube.com/watch?v=hBiCJt6B9Ow
Kahlai, T. (2011, 1 December). Time – AM/PM v 24-hour clock. [Image file]. Retrieved 24 December 2013, from
http://thoikahlai.blogspot.com.au/2011/12/time-ampm-vs-24-hour-clock.html
Mathopolis. (2013). Question 1. [Web quiz]. Retrieved 24 December 2013, from
http://www.mathopolis.com/questions/q.php?id=3698&site=1&ref=/time.html&qs=3698_3699_3700_3701_3702_3703_3704_3705
More Than a Sunday Faith. (2013). Practice = preparation. [Image file]. Retrieved 26 December 2013, from
http://www.morethanasundayfaith.com/2013/09/practice-preparation/
SOLA Optical. (n.d.). Summary. [Image file]. Retrieved 26 December 2013, from http://www.solahistory.com/contents.html