Understanding 24 hour time

Grade 5 lesson (mathematics)

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: Fink, 2013a. [Image file]. “15:10?” He wonders. “What does that mean?”

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). 24 hour time is useful in military, travel and medical industries to avoid confusion. Kahlai , 2011. [Image file].

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: 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 FoundationsA , n.d. [Image file].

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

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: Departure time: 11:00 Flight duration: 3.5 hours Arrival time: _____   Flight #2: Departure time: 15:15 Flight duration: 2.25 hours Arrival time: ______   Flight #3: Departure time: 23:45 Flight duration: 0.75 hours Arrival time: ______   Flight #4: Departure time: 22:45 Flight duration: ______ Arrival time: 00:15 (the next day)

11. Flight #5: Departure time: _____ Flight duration: 2.5 hours Arrival time: 13:30   Flight #6: Departure time: ______ Flight duration: 1 hour 15 minutes Arrival time: 16:00   Flight #7: Departure time: 10:45 Flight duration: ______ Arrival time: 12:30   Flight #8: Departure time: ______ Flight duration: 2 hours 30 minutes Arrival time: 19:15 Flight timetable – fill in the missing pieces!

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-images-happy-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