Activities using Judy clocks help students learn to measure elapsed time.
Main Curriculum Tie:
Mathematics - 3rd Grade
Standard 4 Objective 2
Solve problems involving measurements.
How Do You Know What Time It Is, by Robert E. Wells; ISBN 0807579394
Math Curse, by Jon Scieszka and Lane Smith; ISBN 0670861944
Race Around the Clock
I Have... Who Has... Mental Math Practice Cards- Elapsed Time
Background For Teachers:
Students need to have a basic understanding of how a clock works
and be able to display time to the hour and half hour. They should also
be able to represent a time on an analog clock and duplicate the same
time in digital form. Students should know that 12:00 a.m. is midnight
and 12:00p.m is midday and the times between them are a.m. and p.m.
Students should be familiar with story problems and be able
to understand what the problem is asking by locating the facts
and determining what operation is needed. They should be able to
represent their thinking by expressing their answers on paper.
Intended Learning Outcomes:
5. Connect mathematical ideas within mathematics, to other disciplines, and to
6. Represent mathematical ideas in a variety of ways.
Invitation to Learn
Using math journals have students cut a vertical and horizontal
line in the middle of their paper. They will put a thin line of glue
down the right hand side, gluing it to the page underneath. Fold
back each corner in the center of the page to create a small triangle.
Underneath the triangle place a clock that displays all numbers.
Place clock so that the six and twelve are lined up under the vertical
line and the three and nine line up under the horizontal line. Use
a brad to fasten the hands on the clock. Explain to students that a
clock is divided up into four parts just like and inch. Have them
color each quarter of the clock a different color. Label the top right
fold: quarter after = 15 minutes, lower right fold: two quarters = 30
minutes, lower left fold: three quarters = 45 minutes, and top left
fold: four quarters = 1 hour.
Using a large Judy clock, demonstrate how the minute hand
moves around the clock and as it makes a complete circle the
hour hand moves gradually to the next whole number. Explain to
students that we are going to be learning how much time passes
from a starting time to an ending time. We call this elapsed time.
- Pass out elapsed time rulers. Have students color the left side
from 12:00 a.m. to 12:00 p.m. red and the right side from 12:00
p.m. to 12:00 a.m. blue. Explain how the red side is a.m. and
the blue side indicates p.m. Have students cut out their ruler
and glue it together with the numbers facing out and the 12:00
a.m. marks overlapping. Explain how we can count in the circle
to figure elapsed time.
- On the overhead, use a marker to draw a t-chart. Demonstrate
how we can use a t-chart to figure elapsed time. Jamie put
dinner in the oven at 5:15. It cooked for 2 hours. What time
was the dinner ready to eat? At the top on the left side write
the start time- 5:15. On the top at the other side write hour. In
between the two draw an arrow pointing up to show that we are
counting up. Next, make several horizontal lines going down
the t-chart. Under hour write 1, 2. On the other side, under
5:15, count up the time by hours until it is on the same line as
the 2. The left side should say 6:15, 7:15. The answer is 7:15.
Have the students circle it.
Demonstrate figuring that an activity starts at 4:30 and ends
at 7:30 we can use our t-chart to see how long the activity lasts.
Draw a t-chart. At the top left side write the start time-4:30. On
the top right side write hour. In between the two draw an arrow
pointing up to show that we are counting up. Make several
horizontal lines going down the t-chart. Under the start time
count up by hours, writing them on the line, 5:30, 6:30, 7:30,
until you get to the ending time. On the side with hours count
up by ones to the line that matches on the left side with the
ending time (1,2,3). Circle the 3. This is how much time has
- Using the 28 time problem cards, read a problem and have
the students solve it by using their elapsed time ruler and
a t-chart. Students may use the time problems- work it out
worksheet to help determine what the question is asking.
- Once students understand the concept of elapsed time, play
“Baseball Time”. Baseball Time is created using green poster
board. Use the board so that it is diamond shaped. Place home
plate at the bottom and the three other plates in a diamond
shape to home plate. You will need a baseball clipart for each
student. Divide the class into two teams (A and B). Team
A is “up” first. One at a time, give each student a time story
problem. If the problem is answered correctly, the player
scores a hit and all the players on base advance one base. If the
answer is incorrect, the player scores an out. After one team
has scored three outs, the next team is up. All students have
a Judy clock and are figuring the problem at the same time as
the student that is up to bat.
The team with the most points wins.
- Advanced learners could figure time to the minute. On the right
side of the t-chart they would write minute and count either by
1, 5 or 10 to get to the correct time on the left side.
- When students feel confident with figuring elapsed time, have
them play “I have...Who has?”
- Encourage students to create problems at home and then figure
elapsed time. Example; Dad leaves for work at 7:30 a.m. and
returns home at 5:30 p.m. How many hours did Dad work?
- As students are playing “Baseball Time” teacher will assess
knowledge of concept by verbal responses to problems.
- Journal Entry- Have students draw two clocks in their journal.
On the first clock, have them draw the hands to tell what
time, to the closest quarter hour, they start school. On the
second clock, they will draw hands to tell what time (to the
closest quarter hour) they get out of school. Using a t-chart to
determine how many hours they are in school.
Heddens, J. W., Improving Mathematics Teaching
What are manipulative materials? Manipulative materials are
concrete models that involve math and can be touched and moved
around by the students. They must be materials that relate to the
students’ real world. They should be selected for the appropriate
concept being developed and on the appropriate level for the students.
Battle, T. S., (2007) Infusing Math Manipulatives: The Key to an Increase in Academic
Achievement in the Mathematics Classroom. (ERIC identifier: ED498579). Retrieved
January 8,2008, from www.eric.ed.gov.
Due to the lack of interest and understanding of concepts, students
struggle in mathematics. Research shows that students’ achievement
increases when manipulatives are incorporated in a lesson. When students are actively learning using manipulative materials they are
able to apply what they learn to their own lives, thus forming a link
between concrete and abstract learning.
Created Date :
Jul 08 2008 21:53 PM