Materials
1 paper fastener per student
Scissors
Clock and cards copied on cardstock
Paper lunch bags, 1 per group
Topic
Using a clock
Key Question
What is your ending time after you’ve grabbed some
minutes?
Background Information
Proficiency in telling time can be gained through
hands-on practice. Using a playful format, students are
asked to move the clock hands forward or backward a
specified number of minutes. One means of doing this
is to mentally add or subtract the number of minutes
from the current time on the clock. Another means
is simply by counting forwards or backwards while
moving the hands of the clock. With the 5-minute
cards, counting by fives can be reinforced. Attention
must be paid to changing the hour hand position as
well as the minute hand.
Focus
Students will gain proficiency in telling time by
drawing cards and changing clock hands forwards or
backwards the specified number of minutes. After a
series of draws, the ending time can be checked with
addition and subtraction.
Guiding Documents
Project 2061 Benchmarks
• Numbers and shapes—and operations on them—
help to describe and predict things about the world
around us.
• Tables and graphs can show how values of one
quantity are related to values of another.
• Add, subtract, multiply, and divide whole numbers
mentally, on paper, and with a calculator.
Management
1. Choose the card page which is most appropriate
for your students’ skill level. The first set of cards
has 5-minute increments all under one hour. The
second set of cards has 1-minute increments under
one hour, more of a challenge. The third set of cards
has 5-minute increments of 60 minutes or more
and requires some mental unit conversion from
minutes to hours. The third set may be combined
with the first set once students have developed
proficiency.
2. Make copies of the clock page and the chosen
card page on cardstock. You may wish to laminate
the cards. Cut out the cards and place them in a
lunch bag.
NCTM Standards 2000*
• Recognize the attributes of length, volume, weight,
area, and time
• Carr y out simple unit conversions, such as
from centimeters to meters, within a system of
measurement
• Select and apply appropriate standard units and
tools to measure length, area, volume, weight, time,
temperature, and the size of angles
• Develop fluency in adding, subtracting, multiplying,
and dividing whole numbers
Procedure
1. Inform students that they will be using a homemade
clock and some cards to play a time game.
Distribute the clock page and have students
assemble the clock.
2. Ask someone to give the class a starting time that
is on the hour, such as 3:00. Direct the class to set
their clocks to that time. (In subsequent games,
students could start on the half hour or a 5-minute
increment.)
3. Give students the recording page. Instruct them to
write the starting time in the table.
Math
Measurement
time
unit conversion (60-Minute Plus Cards)
Whole number operations
addition, subtraction
Mental math
Integrated Processes
Observing
Collecting and recording data
Comparing and contrasting
Applying
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© 2005 AIMS Education Foundation
8. Continue with another round of the game as a class
or divide into small groups, each having a grab bag
of cards and picking their own starting times. This
may also be done as a center.
4. Have a student draw a card from the bag and read
it aloud. Guide the class in changing their clocks
to reflect the card’s direction. Ask, “What time is
it now?” To assess students’ success or problems
as you go through the activity, have them hold up
their clocks after each move.
5. Show students how to record in the table. Explain
that “FORWARD 15 minutes” can be abbreviated to
“F-15” in the table. Likewise, “BACK 20 minutes”
can be recorded as “B-20.” This saves time and is
helpful for students with language difficulties.
6. Continue having students draw cards, changing
their clocks, and recording each step until the table
is complete. Point out that, while they are focusing
on minutes, changes will need to be made to the
position of the hour hand as well.
7. Teach students how to assess their own work, if
appropriate. Have them add all the “FORWARD”
minutes in one problem and all the “BACK”
minutes in another problem. Find the difference
between these two answers and recognize whether
“FORWARD” or “BACK” is in the lead. Accordingly,
add or subtract this amount from the starting time.
This gives the correct ending time.
Discussion
1. Was it easier for you to use the clock or add and
subtract the time? Explain.
2. Why is it sometimes difficult to add and subtract
the time?
3. When might you come across a situation in which
you have to add minutes to a starting time? [baking
cookies, returning a phone call, etc.]
4. When might you come across a situation in which
you have to subtract minutes? [knowing how much
time remains before recess or a special television
program, etc.]
Extensions
1. If your students need a further challenge, make your
own cards which combine 1-minute intervals with
numbers greater than one hour. Examples might
include 68 minutes, 84 minutes, 71 minutes, and
127 minutes.
2. This same format can be adapted to moving
forwards and backwards a specified number of
days or weeks on a calendar.
Example:
3:00
F-20
3:20
F-45
4:05
B-25
3:40
F-10
3:50
B-50
3:00
B-20
2:40
F-15
2:55
F-30
3:25
Forward
1
20
45
10
15
+ 30
120
start
TIME
Curriculum Correlation
Literature
Axelrod, Amy. Pigs on a Blanket: Fun with Math
and Time. Aladdin Paperbacks (Simon & Schuster).
New York. 1996. (Mentally add the time it takes for
a family of pigs to travel to the beach, with many
diversions along the way.)
*
Reprinted with permission from Principles and Standards for
School Mathematics, 2000 by the National Council of Teachers
of Mathematics. All rights reserved.
end
CARD
Back
Difference
25
50
+ 20
95
120 F
– 95 B
25
25 minutes F
According to the calculations, if 3:00 is the starting
time, the ending time should be 3:25.
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© 2005 AIMS Education Foundation
Key Question
What is your ending time
after you’ve grabbed
some minutes?
Learning Goal
gain proficiency in telling time by drawing
cards and changing clock hands forwards
or backwards the specified number of
minutes.
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© 2005 AIMS Education Foundation
Set your clock to the starting time. Draw a card and move
the clock hands to the new time. Record in the table.
start
TIME
TIME
start
CARD
end
end
CARD
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© 2005 AIMS Education Foundation
"
"
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© 2005 AIMS Education Foundation
Five-Minute Cards
15 minutes
25 minutes
10 minutes
30 minutes
40 minutes
25 minutes
20 minutes
10 minutes
50 minutes
55 minutes
30 minutes
45 minutes
45 minutes
20 minutes
15 minutes
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© 2005 AIMS Education Foundation
One-Minute Cards
3 minutes
9 minutes
7 minutes
17 minutes
12 minutes
23 minutes
11 minutes
8 minutes
14 minutes
24 minutes
4 minutes
33 minutes
32 minutes
19 minutes
16 minutes
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© 2005 AIMS Education Foundation
60-Minute Plus Cards
2 hours,
30 minutes
120 minutes
80 minutes
75 minutes
70 minutes
150 minutes
60 minutes
80 minutes
90 minutes
90 minutes
2 hours,
15 minutes
120 minutes
100 minutes
60 minutes
75 minutes
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© 2005 AIMS Education Foundation
Connecting Learning
1. Was it easier for you to
use the clock or add and
subtract the time? Explain.
2. Why is it sometimes difficult to
add and subtract the time?
3. When might you come across a
situation in which you have to
add minutes to a starting time?
4. When might you come across a
situation in which you have to
subtract minutes?
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© 2005 AIMS Education Foundation