Time_ Section 3_Beg-Numeracy
Time: Beginning Numeracy
Section 3: Calculating Time across AM and PM
EL Civics 2011-13
Unit Description:
This unit is divided into three sections with each section having 3 to 5 activities. This
document contains teaching materials for Section 3.
 Section 1: Reading Time
 Section 2: Calculating Time within AM or PM
 Section 3: Calculating Time across AM and PM
Ronald Hubbs Center EL Civics 2011-2013
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Time_ Section 3_Beg-Numeracy
AM and PM (S3-A1a)
Change PM hours by counting to 24. Then you can calculate time across AM and PM.
AM Hours
AM Hours
PM Hours
12 AM 24
11
11
23
10
10
22
9
9
21
8
8
20
7
7
19
6
6
18
PM Hours
(12 AM = 0000 military time but 24 works for our purposes)
24/12
5
5
17
4
4
16
3
3
15
23
13
22
14
15
21
2
2
14
1
1
13
12
12
12
Ronald Hubbs Center EL Civics 2011-2013
20
16
19
17
18
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Time_ Section 3_Beg-Numeracy
Matching Hours with Military Time (S3-A1b)
Note: At 12 AM military time is 0000. However, for calculating across AM & PM using 24 is helpful.
Cut out the cards. Match the hours with the military times.
12
1
2
3
4
5
6
7
8
9
10
11
24
16
22
18
0000
1600
2200
1800
17
13
21
19
1700
1300
2100
1900
15
23
14
20
1500
2300
1400
2000
Ronald Hubbs Center EL Civics 2011-2013
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Time_ Section 3_Beg-Numeracy
Finding Elapsed Time across AM & PM (S3-A2)
Ask your classmates these questions and write their answers in the chart.
1. What time do you start classes at the ________________?
school name
2. What time do you finish classes?
Name
1. Start Time
2. End Time
3. Elapsed Time
1. Now work with a small group or with your teacher.
2. Calculate the elapsed time for all the people you talked to.
3. Use this formula: End Time – Start Time = Elapsed Time
Example:
1:15 PM – 8:30 AM = _4 hrs and 45 minutes_
end time – start time =
elapsed time
Step 1: Change end time to “military time”.
13:15 PM
– 8:30 AM
Step 2: Borrow 60 minutes and move it to the minutes place.
borrow 60 minutes
and move into the
minutes place
12:60
75
13:15
-8:30
4:45 = 4 hours and 45 minutes
Step 3: Solve the problem.
Ronald Hubbs Center EL Civics 2011-2013
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Time_ Section 3_Beg-Numeracy
Calculating Time across AM & PM (S3-A3)
Part 1: Finding End Time
Formula: Start Time + Elapsed Time = End Time
4:30 AM + 9 hrs 45 mins = _2:15 PM_
4:30 AM
+9:45 (9 hrs 45 mins)
(+1) 13:75 (-60)
Take 60 minutes from the
Subtract
12 for
PM time
minutes place and carry it to
the hours place. 60 mins = 1 hr.
14:15
-12:00
2:15 PM
Fill in the chart with the missing End Times.
Start Time
6:30 AM
11:20 AM
4:30 PM
8:15 AM
End Time
1.
2.
3.
4.
Elapsed Time
8 hours 10 min. later
12 hours 40 min. later
14 hours 20 min. later
5 hours 30 min. later
Part 2: Finding Start Time
Formula:
End Time - Elapsed Time = Start Time
5:15 PM - 7 hrs 45 mins = 9:30 AM
Change PM time to
“military time”
Borrow 60 minutes
and add to the
minutes place
16:60 75
17:15
-7:45 (7 hrs 45 mins)
9:30 AM
Fill in the chart with the missing Start Times.
Start Time
1.
2.
3.
4.
Ronald Hubbs Center EL Civics 2011-2013
End Time
3:15 PM
3:10 PM
6:15 AM
5:35 AM
5
Elapsed Time
7 hours ago
3 hours 45 min. earlier
9 hours 5 min. before
5 hours 45 min. ago
Time_ Section 3_Beg-Numeracy
Word Problems: Calculating Time (S3-A4)
Read the word problems and find the answers to the questions.
1. Alma’s daughter Linda started class at 9:00 in the morning. It finishes 8
hours later. What time will Linda’s class finish?
2. Your sister is coming to pick you up from class at HUBBS. She calls you at
12:30 and says she will be there 1 hour and 10 minutes later to pick you
up. What time will she arrive at HUBBS?
3. Your baby woke up this morning at 5:00 AM. The baby fell asleep 10
hours ago. What time did the baby fall asleep?
4. At four thirty the bus arrived at our house to drop off the children. They
were gone for seven hours and forty minutes. What time did they leave
for school?
Ronald Hubbs Center EL Civics 2011-2013
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Time_ Section 3_Beg-Numeracy
Yesterday’s Activities (S3a)
What did you do yesterday?
Write 6 activities below. Write when you started and when you finished.
Now calculate the elapsed time for each activity. You can work with a partner.
Activity
Start Time
End Time
Elapsed Time
1.
2.
3.
4.
5.
6. Sleep
Now take a survey of your class.
Ask the questions and put a tally ( / ) in the correct column.
Less than
1 hour
1 to 3
hours
3 to 5
hours
5 to 8
hours
Over 8
hours
1. How long did you watch
TV yesterday?
2. How long were you in
classes yesterday?
3. How long did you work
yesterday?
4. How long did you do
housework?
5. How long did you sleep
yesterday?
Answer these questions:
1. How many students watched more than 3 hours of TV yesterday?
2. How many students worked more than 8 hours yesterday?
3. How many students slept more than 8 hours yesterday?
4. How many students slept less than 5 hours yesterday?
5. How many students did 1 to 3 hours of housework yesterday?
Now write 1 question: ____________________________________________?
Ronald Hubbs Center EL Civics 2011-2013
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Time_ Section 3_Beg-Numeracy
Quiz: Calculating Time across AM & PM (S3b)
Part 1: Calculating Time: Fill in the chart with the missing information.
Start Time
1.
2.
3.
4.
5.
6.
7.
8.
End Time
5:15 PM
Elapsed Time
6 hours ago
6:30 AM
10 hours 5 min. later
8 hours 5 min. before
12:30 PM
12 hours 45 min. ago
10 hours 15 min. ago
6:30 AM
5:35 AM
11:20 AM
10:30 PM
4:30 PM
12 hours 40 min. later
14 hours 25 min. ago
14 hours 40 min. later
Part 2: Word Problems
Read the word problems and find the answers to the questions.
1. Alma’s daughter Linda started class at 8:30 in the morning. It finishes 8
hours and 15 minutes later. What time will Linda’s class finish?
2. Your sister is coming to pick you up from class at HUBBS. She calls you at
12:15 and says she will be there 1 hour and 30 minutes later to pick you
up. What time will she arrive at HUBBS?
3. Your baby woke up this morning at 4:00 AM. The baby fell asleep 9
hours ago. What time did the baby fall asleep?
4. At four fifteen the bus arrived at our house to drop off the children.
They were gone for seven hours and thirty minutes. What time did they
get home?
Ronald Hubbs Center EL Civics 2011-2013
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