Watch It! Elapsed Time Clock EI-1724 Anleitung Seite 3

Suggested Classroom Activities
Use the Elapsed Time Clock can be used as a whole-class activity or place it at a
center for independent work.
Calculating Elapsed Time—Difference Between Two Times
Pose an elapsed time problem. For example, The birthday party started at 2
and ended at 5
p
To solve, set the START watch to 2:00
watch to 5:00 .
p
Then, ask students how long they think the party
lasted. Note: You can help students to calculate this by
setting both watches to 2:00
END watch minute hand 3 times around slowly until
you reach 5:00
p
Once students have given their answers, press the
button on the top of the stopwatch to reveal the
answer.
Adding Time—What Time Will It Be?
Calculating a Future Event Time
Pose a question such as, It's 7:45
to school. If Eric leaves now, what time will he arrive at school?
To solve, set both the START and END watches to
7:45 . .
a m
Next, open the ELAPSED TIME stopwatch window
door. It should read 0:00 because both watches are
currently set to the same time.
While watching the ELAPSED TIME window, move the
minute hand on the END watch clockwise until the
window reads 15 minutes.
What time does the END watch read now? (8:00
That is the time that Eric will arrive at school.
. . How long was the party?
m
.
m
.
p m
. .
m
. . and the END
p m
. and then moving the
. . right now. It takes 15 minutes for Eric to walk
a m
. .)
a m
. .
p m
Figure 6
Figure 7
Figure 8
Figure 9
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