1. Elapsed Time I can determine elapsed time in hours and minutes within a 24-hour period using a clock with 80% accuracy.

2. Day 1

3. Elapsed Time The difference between two times.

4. Steps to figuring out the elapsed time between two times Figure out how many hours are between the two times Figure out how many minutes are between the two times Put the hours and minutes together

5. Step 1 Count the Hours 7:10 – 10:55 7:10-8:10 = 1 hour 8:10-9:10 = 1 hour 9:10-10:10 = 1 hour

6. Step 1 Count the Hours 1 hour + 1 hour + 1 hour = 3 hours

7. Step 2 Count the Minutes **Start with the last hour you wrote 10:10-10:55

8. Step 2 10:10-10:20 = 10 minutes 10:20-10:30 = 10 minutes 10:30-10:40 = 10 minutes 10:40-10:50 = 10 minutes 10:50-10:55 = 5 minutes

9. Step 2 Add up the minutes 10 + 10 + 10 + 10 + 5 = 45 minutes

10. Step 3 Put the hours and minutes together 3 hours and 45 minutes

11. How long does it take to fly from Houston to Orlando? Departure Time Houston 8:00 am Arrival Time Orlando 11:10 am From 8:00 am to 11:00 am is 3 hours. Count 10 minutes from 11:00 am until 11:10 am

12. ANSWER It takes 3 hours and 10 minutes to fly from Houston to Orlando.

13. Your dance partner arrives at 3:30 pm and leaves at 7:45 pm. How long did you practice together? Count the hours 3:30 – 7:00 (4 hours) Count the minutes 7:00-7:15 (15 minutes) You practiced 4 hours and 15 minutes together.

14. The sun set at 7:00 pm. It rose the next morning at 5:15 am. How much time passed from sunset to sunrise? Count the hours 7:00 – 5:15 (10 hours) Count the minutes 7:00 – 5:15 (15 minutes) From sunset to sunrise, there was 10 hours and 15 minutes.

15. Day 2

16. Finding the ending time Begin with the start time Add the hours Add the minutes Write the ending time

17. Example: Hope and Charlie went for a walk at 5:34 PM. They walked for 2 hours and 18 minutes. What time did they get home? Add the hours: 5:34-6:34 = 1 st hour 6:34-7:34 = 2 nd hour

18. Example Hope and Charlie went for a walk at 5:34 PM. They walked for 2 hours and 18 minutes. What time did they get home? Add the minutes (start with the last hour added): 7:34-7:35 = 1 minute 7:35-7:40 = 5 minutes 7:40-7:45 = 5 minutes 7:45-7:50 = 5 minutes 7:50-7:52 = 2 minutes 18 minutes

19. Example: Write down the ending time: 7:52 PM

20. Natalie and Maria left the school at 3:05 pm. They walked for 1 hour 14 minutes before arriving at Maria’s house. What time did they arrive at Maria’s house? Find the hours: 3:05 – 4:05 = 1 hour Find the minutes: 4:05 – 4:19 = 14 minutes They got to Maria’s at 4:19 PM.

21. Mario scored his first touchdown at 7:48 pm. Julio intercepted a pass and scored a touchdown 2 hours 4 minutes later. What time did Julio score the second touchdown? Find the hours: 7:48 – 9:48 = 2 hours Find the minutes: 9:48 – 9:52 = 4 minutes He scored the 2 nd touchdown at 9:52 PM

22. Day 3

23. Finding the start time Start with the end time Work backwards with the minutes Work backwards with the hours Write the start time

24. Example: Mrs. Breen was baking cookies for the 5 th grade. She baked for 3 hours and 12 minutes. If she finished cooking at 8:25 PM, what time did she start baking? Work with the minutes: 8:25-8:20 = 5 minutes 8:20-8:15 = 5 minutes 8:15-8:13 = 2 minutes 12 minutes

25. Example: Mrs. Breen was baking cookies for the 5 th grade. She baked for 3 hours and 12 minutes. If she finished cooking at 8:25 PM, what time did she start baking? Work with the hours: 8:13-7:13 = 1 hour 7:13-6:13 = 1 hour 6:13-5:13 = 1 hour 3 hours

26. Example: Write down the start time: 5:13 PM

27. The Garza’s will visit their cousin, who lives 3 hours and 10 minutes away. They want to get there at 11:30 am. What time should they leave? Find the minutes: 11:30 – 11:20 = 10 minutes Find the hours: 11:20 – 8:20 = 3 hours They need to leave at 8:20 am.

28. The Collins’s will visit their cousin, who lives 6 hours and 13 minutes away. They want to get there at 10:45 am. What time should they leave? Find the minutes: 10:45 – 10:32 = 13 minutes Find the hours: 10:32 – 4:32 = 6 hours They need to leave at 4:32 am.

29. Day 4

30. Your Turn Click here: http://marg.mhost.com/MathGr5/elapsedtime.htm