1. Use Time Intervals
How can you find a starting time or an ending time when you know the elapsed time?
MAFS.3.MD.1.1

2. Lesson Opening
Rita started reading a book at 4:03 P.M. She read until one half hour past 4 in the afternoon. For how many minutes did Rita read?

3. Lesson Opening
Rita started reading a book at 4:03 P.M. She read until one half hour past 4 in the afternoon. For how many minutes did Rita read?
10 mins
10 mins
7 mins
4:03
4:13
4:23
4:30

4. Lesson Opening
Rita started reading a book at 4:03 P.M. She read until one half hour past 4 in the afternoon. For how many minutes did Rita read?
10 mins
10 mins
7 mins
4:03
4:13
4:23
4:30
Rita read for 27 minutes.

5. How can you find an ending time when you know the elapsed time?
Mrs. Lester left for Orlando at 7:15 a.m. It took her 2 hours and 30 minutes to get to Orlando. At what time did she arrive in Orlando?

6. How can you find an ending time when you know the elapsed time?
Mrs. Lester left for Orlando at 7:15 a.m. It took her 2 hours and 30 minutes to get to Orlando. At what time did she arrive in Orlando?
1 hour
1 hour
10 mins
10 mins
10 mins
7:15
8:15
9:15
9:25
9:35
9:45
First, add the hours onto the starting time, then add the minutes in 10s, 5s, or 1s.

7. How can you find a starting time when you know the elapsed time?
Pedro needs to get home for dinner by 6:30 P.M. It takes him 45 minutes to drive home from work. When should he leave work to get home on time?

8. How can you find a starting time when you know the elapsed time?
Pedro needs to get home for dinner by 6:30 P.M. It takes him 45 minutes to drive home from work. When should he leave work to get home on time?
Start at the ending time and jump backwards to find the starting time.

9. How can you find a starting time when you know the elapsed time?
Pedro needs to get home for dinner by 6:30 P.M. It takes him 45 minutes to drive home from work. When should he leave work to get home on time?
6:30
Start at the ending time and jump backwards to find the starting time.

10. How can you find a starting time when you know the elapsed time?
Pedro needs to get home for dinner by 6:30 P.M. It takes him 45 minutes to drive home from work. When should he leave work to get home on time?
-5 min
-10 min
-10 min
-10 min
-10 min
5:45
5:50
6:00
6:10
6:20
6:30
Count the hours back, then the minutes by 10s, 5s, and 1s.

11. How can you find a starting time when you know the elapsed time?
Pedro needs to get home for dinner by 6:30 P.M. It takes him 45 minutes to drive home from work. When should he leave work to get home on time?
5 mins
40 minutes
-5 min
-10 min
-10 min
-10 min
-10 min
5:45
5:50
6:00
6:10
6:20
6:30
He should leave for work at 5:45 P.M. to get home on time.

12. Exit Ticket
If you want to be at school at 7:45 a.m. and it takes you 70 minutes to get ready, eat breakfast, and walk to school, what time do you need to wake up?