Time-Based Math Strategies for Elementary Students
Learn how to use open number lines, addition, subtraction, and elapsed time strategies with practical examples and explanations for elementary students. Improve math skills in a fun and engaging way!
Time-Based Math Strategies for Elementary Students
E N D
Presentation Transcript
Elapsed Time Open Number Line
Open Number Line Strategies for Addition
Addition – Can someone explain what is happening here? • 36 + 24 +4 +10 +10 36 60 46 56 36 + 24 = 60
Addition – Can someone explain what is happening here? • 36 + 24 +10 +10 +4 36 60 40 50 36 + 24 = 60
Addition – Can someone explain what is happening here? • 36 + 24 +20 +4 36 60 56 36 + 24 = 60
Open Number Line Strategies for Subtraction
Subtraction – Can someone explain what is happening here? • 53 - 37 Strategy: count up from the smallest number +3 +3 +10 10 + 3 + 3 = 16 37 53 47 50 53 - 37 = 16
Subtraction – Can someone explain what is happening here? • 53 - 37 Strategy: count back from the largest number -3 -10 -3 3 + 3 + 10 = 16 37 53 40 43 53 - 37 = 16
Subtraction – Student 3 • 53 - 37 Strategy: count back from the largest number -3 -10 -10 -4 -10 16 53 20 33 43 23 53 - 37 = 16
Elapsed Time Using Benchmarks
How long is the movie? • I started watching a movie at 3:30 pm and it ended at 4:45 pm.
Elapsed Time • The movie started at 3:30 and ended at 4:45. How long was the movie? +30 min +30 min +15 min Strategy: Start at 3:30 and add time increments to the hour or ½ hour, (benchmarks), then continue until end time. 3:30 4:45 4:00 4:30 30 + 30 + 15 = 75 minutes = 1 hour 15 minutes
How much time is there between school and bedtime? • How much time is there between the time school is out (3:40 pm) and bedtime (8:15 pm)?
Elapsed Time – using benchmarks • How much time is there between 3:40 and 8:15? Strategy: Start at 3:40 and add time increments to the ½ hour benchmarks, then continue increments. +20 min +4 hours +15 min 3:40 8:15 4:00 8:00 4 hours + 20 min. + 15 min.= 4 hours 35 minutes
Time over the 12:00 hour • How much time is there between 10:30 am and 2:45 pm?
Elapsed Time – over 12 o’clock hour • How much time is there between 10:30 am and 2:45 pm? +30 min. +1 hour +2 hours +45 min Strategy: Add increments to 12:00, then continue benchmark increments. 2:45 2:00 11:00 12:00 noon 10:30 1 hr. + 2 hr. + 30 min. + 45 min. = 3 hr. 75 min. = 4 hr. 15 min.
Find the ending time • What time is 4 hours and 30 minutes from 6:55?
Finding the ending time – • What time is it 4 hours and 30 minutes from 6:55? Strategy: Add minute increments to the ½ hour benchmark, then hours, then minutes. +4 hr. +5 min +25 min 11:00 11:25 7:00 6:55 The time is11:25, which is 4 hrs. and 30 min. after 6:55.
Finding the ending time – • What time is it 4 hours and 30 minutes from 6:55? Strategy: Add hour increments until close, then minutes to the ½ hour, then minutes. +1 hr. +1 hr. +1 hr. +1 hr. +5 min +25min 11:00 11:25 7:55 8:55 10:55 6:55 9:55 The time is11:25, which is 4 hrs. and 30 min. after 6:55.
Find the start time • What time did we start on our trip if we arrived at 8:17 and it took 3 hours and 10 minutes?
Finding the start time • What time did we start on our trip if we arrived at 8:17 and it took 3 hours and 10 minutes? -10 min. -3 hr. Strategy: Subtract the hours then minutes. 8:17 5:07 5:17 The start time is 5:07.
Find the start time • What time do I need to wake up if I have to be at school at 8:15 am and it takes me 1 hour and 45 minutes to get ready?
Finding the start time • What time do I need to wake up if I have to be at school at 8:15 am and it takes me 1 hour and 45 minutes to get ready? -1 hr. -15 min. -15 min. -15 min. Strategy: Subtract the hour, then minute benchmarks. 8:15 6:30 6:45 7:00 7:15 I have to wake up at 6:30 AM.