Mastering Time Intervals with the 24-Hour Clock

1. Measures and Data Read timetables using 24-hour clock Calculate time intervals Objectives Day 1 Calculate time intervals using the 24-hour clock. Day 2 Read timetables and calculate time intervals using the 24-hour clock. Day 3 Read timetables using the 24-hour clock. Calculate time intervals. Day 4 Given a time delay, count on to find new train departure and arrival times. Year 5

2. Measures and Data Read timetables using 24-hour clock Calculate time intervals Starters Day 1 Read the 24-hour clock (pre-requisite skills) Day 2 Converting between 12-hour and 24-hour clock (pre-requisite skills) Day 3 Pairs to 60 (simmering skills) Day 4 Units of time (simmering skills) Year 5

3. Measures and Data Read timetables using 24-hour clock Calculate time intervals Starter Read the 24-hour clock Year 5

4. Measures and Data Read timetables using 24-hour clock Calculate time intervals Starter • Converting between 12-hour and 24-hour clock Year 5

5. Measures and Data Read timetables using 24-hour clock Calculate time intervals Starter Pairs to 60 Year 5

6. Measures and Data Read timetables using 24-hour clock Calculate time intervals Starter • Units of time Year 5

7. Measures and Data Read timetables using 24-hour clock Calculate time intervals Objectives Day 1 Calculate time intervals using the 24-hour clock. Year 5

8. Day 1: Calculate time intervals using the 24-hour clock. • This is a 24-hour digital clock. What would this time look like on a 12-hour digital clock? • When is it useful to use a • 24-hour digital clock rather than a 12-hour digital clock? 1 6 3 0 • Hours • Minutes • A school science lesson starts at 10:45 and ends at 11:35. • How long does it last? • Sketch a time number line to represent this on your whiteboard. How many minutes until 11 o’clock? Remember that we are counting up to 60, not 100… 11:00 35 mins 15 mins 10:45 11:35 15 mins + 35 mins = 50 mins Year 5

9. Day 1: Calculate time intervals using the 24-hour clock. • A P.E. lesson starts at 13:30 and ends at 14:45. • How long does it last? • Sketch a time number line to represent this on your whiteboard. • A singing lesson starts at 11:50 and ends at 12:35. • How long does it last? • Sketch a time number line to represent this on your whiteboard. Compare your timeline with your partner's. Compare your timeline with your partner's. Year 5

10. Challenge Year 5

11. Measures and Data Read timetables using 24-hour clock Calculate time intervals Objectives Day 2 Read timetables and calculate time intervals using the 24-hour clock. Year 5

12. Day 2: Read timetables and calculate time intervals using the 24-hour clock. • I am going to show a time in 12-hour format. • Convert it to 24-hour format, search for it on the timetable and write the corresponding place name on your whiteboard. • What time does the 08:45 reach Ottery St Catchpole? Write both the 24-hour and 12-hour times on your whiteboard. • 2 minutes past 9 in the morning. • 10 to 7 in the evening. • Five to midnight. • 20 past 5 in the afternoon. Year 5

13. Day 2: Read timetables and calculate time intervals using the 24-hour clock. I am going to ask you to calculate time intervals. Draw time-lines to help. • How long does the 08:45 from Diagon Alley take to reach Ottery St Catchpole? • How long does the 19:52 from Kings Cross take to reach Hogsmeade? • Which is the fastest train between Kings Cross and Hogwarts? Year 5

14. Day 2: Read timetables and calculate time intervals using the 24-hour clock. Whole Class activity • For each route, find how long the train takes between Diagon Alley and Kings Cross. What do you notice? • Investigate journey times between other pairs of stations. In each case, find the quickest and the slowest journey times. Year 5

15. Year 5

16. Measures and Data Read timetables using 24-hour clock Calculate time intervals Objectives Day 3 Read timetables using the 24-hour clock. Calculate time intervals. Year 5

17. Day 3: Read timetables using the 24-hour clock; Calculate time intervals. • Hikers can get off on the moors to go walking, or holiday-makers can get the train to the seaside at Whitby. • North Yorkshire Steam Railway runs steam trains from Pickering across the moors to Whitby on the coast. • Write ringed times as 12-hour times. Year 5

18. Day 3: Read timetables using the 24-hour clock; Calculate time intervals. • A family want to catch the first train from Pickering to Whitby, and catch the last train back so they can have a full day at the seaside. • We’re going to find out how long they can spend in Whitby. What should we mark on the time-line? Year 5

19. Day 3: Read timetables using the 24-hour clock; Calculate time intervals. Arrive in Whitby at 10:35. Leave Whitby at 17:30. They can stay in Whitby for 6 hours 55 minutes. 11:00 17:00 6 hours 30 mins 25 mins 10:35 17:30 6 hours + 25 mins + 30 mins = 6 hours 55 mins Year 5

20. Day 3: Read timetables using the 24-hour clock; Calculate time intervals. • A group of walkers is staying in Whitby. They want to do a walk on the moors, starting at Newtondale and finishing at Grosmont. This walk should take about 4 hours. Look at the timetable and give the group some travel advice. Year 5

21. Challenge Year 5

22. Measures and Data Read timetables using 24-hour clock Calculate time intervals Objectives Day 4 Given a time delay, count on to find new train departure and arrival times. Year 5

23. Day 4: Given a time delay, count on to find new train departure and arrival times. The 14:48 to Birmingham New Street is running approximately 37 minutes late as a result of sheep on the line near Worcester. • How will we calculate the new departure time? • How many minutes to the next hour? • How many minutes do we need to add? 15:00 15:25 25 mins 12 mins 14:48 • So this is the time that the train is now expected to depart. Year 5

24. Day 4: Given a time delay, count on to find new train departure and arrival times. The train to Gloucester, due to depart at 18:52, is running approximately 45 minutes late as a result of signalling problems. Calculate the new departure time. Calculate the new departure time. The 13:53 to Penzance is running approximately 1 hour and 15 minutes late as a result of stormy weather conditions causing flooding. Year 5

25. Year 5

26. Measures and Data Read timetables using 24-hour clock Calculate time intervals Well Done! You’ve completed this unit. Objectives Day 1 Calculate time intervals using the 24-hour clock Day 2 Read timetables and calculate time intervals using the 24-hour clock Day 3 Read timetables using the 24-hour clock. Calculate time intervals. Day 4 Given a time delay, count on to find new train departure and arrival times. Year 5

27. Problem solving and reasoning questions True or false? • 13:40 is twenty to two in the afternoon. • Midnight is 00:00 • Midday is 12:00 on 24 hour clock • 19:15 is quarter past 7 in the morning. • 1 hour after 15:00 is six o’clock pm. Calculate how long it is between… • 13:40 and five to 5 in the afternoon • Quarter to midday and 17:23 • Five past midnight and ten to midday If each bus is 40 minutes late, write its new arrival time. (i) No. 31 bus due at 12:55 (ii) No. 22 bus due at 13:04 (iii) No. 15 bus due at 14:44 The number 4A bus arrived 27 minutes late at 00:14. What time was it due? Year 5

28. Problem solving and reasoning: Answers • True or false? • • 13:40 is twenty to two in the afternoon. True • • Midnight is 00:00 True • • Midday is 12:00 on 24 hour clock True • • 19:15 is quarter past 7 in the morning. False - it is in the evening • • 1 hour after 15:00 is six o’clock pm. False - it is four o’clock pm • Calculate how long it is between… • • 13:40 and five to 5 in the afternoon 3 hours 15 minutes • • Quarter to midday and 17:23 5 hours and 38 minutes • • Five past midnight and ten to midday 11 hours and 45 minutes. • An ENL jotting can help with these calculations, which are probably best-solved by counting up from the earlier to the later time. • If each bus is 40 minutes late, write its new arrival time. • (i) No. 31 bus due at 12:55 13:35 • (ii) No. 22 bus due at 13:04 13:44 • No. 15 bus due at 14:44 15:24 • Answers of 12:95 and 14:84 for (i) and (iii) respectively suggest child had added the minutes but forgotten that there are only 60mins in an hour. • The number 4A bus arrived 27 minutes late at 00:14. What time was it due? • 23:47 Year 5