THE RESULTS FROM THE THIRD INTERNATIONAL Mathematics and Science Study
(TIMSS), which tested a half million eighth-grade students in forty-one
countries, have recently been publicized. Students in the United States
ranked below average in mathematics, whereas students in Singapore earned
top scores. Examining how students in Singapore study mathematics should
provide useful information to mathematics educators on how to improve
the performance of students in the United States. Problem solving is emphasized
in Singapore, where students are expected to struggle with problems that
have real-life implications.
THE
ACTIVITY THE PACKETS PROBLEMS, DEVELOPED BY Educational Testing
Service (1995), is a collection of mathematical activities that allow
students to develop several ideas as they struggle through real-life situations.
The problems are aligned with the NCTM's Standards and facilitate linking
instruction with assessment. Students can practice skills that they have
already acquired and develop new skills and concepts. In each problem,
a specific task requires mathematical thought and organization. The multiple
acceptable solutions are based on the parameters that the students themselves
design in interpreting the problem. Providing justification for their
solutions is an important element of the activities, and a rubric helps
to assess the strength of the student's argument. The following is "The
Million Dollar Getaway":
Main Bank was robbed this morning. A lone robber carried the loot away
in a big leather bag. The manager of the bank said most of the stolen
bills were ones, fives, and tens. Early reports said the robber took approximately
$1 million in bills. The Channel 1 News team thinks this sounds like more
money than one person could carry. What do you think? Channel 1 News needs
help in determining how hard it would be for one person to carry $1 million
in small bills.
Please
investigate this question to determine if this is possible. Prepare a
report for Channel 1 News describing and explaining your findings. Your
report should help the investigative reporter at Channel 1 better understand
the situation to plan for tonight's broadcast.
The
goal is for students to create a report to submit to the news station.
The problem involves such mathematical strands as geometry; measurement;
whole-number fraction and decimal computation; volume, area, and weight;
and estimation. In addition to "content" strands, such "process" strands
as communication, reasoning, problem solving, and making connections are
developed.
A
RATIONALE FOR INCLUSION THE PROBLEM WAS IMPLEMENTED IN A FIFTH-grade class
at Magen David Yeshiva in Brooklyn, New York. Five of the students, who
were weak in basic mathematics skills and concepts, regularly left the
room to work on a modified mathematics curriculum. This practice seemed
to run counter to the newly instituted inclusion in a regular classroom
setting for language-arts students who had previously been in a reading-resource
room. The concept of inclusion has attracted international attention.
The 1997 RISE (Restructuring for Inclusive School Environments) conference
featured a program on "International Perspectives on Inclusion." The rationale
behind inclusion is that rather than leave the room for a modified program,
students should have a teacher who is trained to implement the program.
We decided, then, to use the inclusion model by having the five students
work within the classroom with the regular teacher present. The goal was
to provide these students with a problem-solving experience within a larger
community, as well as to build their self-esteem by having them participate
as an integral part of the regular class. All students received the same
information and task, and the problem-solving approach was open-ended.
No steps were specified for the task. Sylvia Bulgar taught the regular
class, and Lynn Tarlow taught the modified group. Although Tarlow remained
primarily with the modified group, both teachers were available for all
students.
ASSESSMENT
CRITERIA AN ASSESSMENT OF THE WORK WAS BASED ON examining the final product
(the letter to the news station) as well as observing the processes that
the students used to develop their ideas. The categories for assessment
included problem-solving strategies, communication while solving the problem,
demonstrating understanding of mathematics concepts, and completeness
of the answer. An evaluation of the written product, in this case, the
report to the news station, was based on the criteria set forth by the
PACKETS program. Written products are assessed as being one of the following:
noteworthy (not only achieves the client's immediate objectives but also
addresses larger objectives), acceptable (achieves the client's objectives,
needs minor revision), closely (resembles what a complete response would
look like but fails to provide in a usable form everything that is necessary),
needs major revision (demonstrates a basic understanding of the problem
and a reasonable start but needs substantial work before it will be useful),
and needs redirection (indicates a lack of understanding about the problem
or a lack of useful ideas about how to solve it.)
COMPOSITION
OF THE GROUPS NINETEEN STUDENTS, PLACED into four homogeneous groups,
participated in the activity. Creating homogeneous groups encourages all
students within each group to participate in developing the solution.
Students learning in a constructivist environment typically work in homogeneous
pairs or groups. Although such groupings remain controversial, the teachers
involved decided to implement this methodology. Students were grouped
according to past performances in mathematics-problem-solving activities.
Group 1 comprised five students who had demonstrated the strongest ability
in mathematical problem solving. Group 2 consisted of five students who
had previously formed the second tier. Group 3 contained four students
who had demonstrated average ability in problem solving. Group 4 consisted
of five students who were regularly taken out of the classroom for a modified
mathematics program.
GETTING
STARTED ALL STUDENTS HAD DIFFICULTY GETTING started. They had to be reassured
that they were not expected to solve this problem in one session and that
they would struggle to find a solution. Many complaints arose about the
problem's being too difficult, especially from group 2.
GROUP
3'S RESULTS Group 3 began by using Unifix cubes to represent the money.
They had found this manipulative to be useful in solving several previous
problems and apparently decided to use the cubes without considering whether
they would be appropriate. After several attempts to create a model of
the money, they discussed what $1 million looked like. Some group members
did not really understand the concept of one million. Some could represent
the number as being one thousand thousands; however, group members still
were unable to map this representation to a concrete model. Apparently,
rote knowledge that one million is equal to one thousand thousands was
inadequate for understanding the value of the number.
After
a discussion about how much the number 1 000 000 actually was, the group
decided to cut out paper to represent the money. They would take one student's
leather knapsack, empty it, and see whether all the money would fit inside.
On the second day, this group discussed the weight and the volume of the
money. The students theorized that if all the money would fit into the
knapsack, then it would not be too heavy to carry. They did not, however,
attempt to weigh the money to justify this theory. This group spent a
lot of time trying to make $1 000 000 in fake dollars, later deciding
to make only half of the $1 000 000 and see how much space it used in
the bag. They reasoned that they could estimate whether the entire amount
of money would fit in the bag. They saw the significance of estimation
as a useful tool to make problem-solving tasks more manageable.
This
group was the first to complete the product (i.e., the report to the news
station). Their product would fall under the category of "needs minor
revision," since it could be improved by adding specific information regarding
dimensions. The solution alludes to an understanding of volume but does
not refer to specific measurements. A discussion of volume would provide
more substantial justification for the group's result. In addition, this
group interpreted the assignment to mean that many large bills could be
included as long as most of them were of small denominations. Their product
would have been better justified had they explained the breakdown of the
bills. The product, however, is clearly written and well organized.
GROUP
2'S RESULTS Group 2 had the most difficulty getting started. They complained
about having no idea of how to begin and sat idle, seemingly overwhelmed
by the task. They then approached a student from group 4 to ask for help.
The students in group 4 are not generally consulted for advice on problems.
Eventually, group 2 saw other groups cutting out paper in the size of
actual money. They planned to cut and measure bills totaling $100 000
and then multiply their results by 10. This strategy shows an understanding
of the concept of 1 000 000.
The
group members used computation accurately and understood that they could
use estimation. They understood the need for accuracy in depicting the
size of the bills. Once they developed a strategy, they worked enthusiastically.
At home they photocopied bills that they cut out to use for their simulation.
This group's product needed major revision. They included a breakdown
of the various denominations and totaled the amount of money for each
denomination. They made accurate use of computation, emphasizing that
they had accounted for the complete $1 000 000. However, at no point did
the group members consider the weight or the volume of the money nor the
total number of bills required to reach $1,000 000.
GROUP 1'S RESULTS Group 1, the first group to begin work, immediately
developed a plan to solve the problem. Members decided that the money
would have to be carried out in a suitcase, so they drew an area model
of a suitcase to represent how the money would be placed in it. They measured
a dollar to figure out how wide and how long the suitcase would have to
be and then figured out how many bills would be needed to make $1 000
000. Initially, they said that they would make false money totaling a
half-million dollars and multiply it by 2. One member suggested that they
could make a quarter of a million simulated dollars and then multiply
by 4, discussing the fact that a quarter of a million dollars was equal
to $250 000. This group worked most efficiently, originating an idea and
continuing to modify it until it was workable.
This
strategy conforms with Papert's (1980) model of debugging, wherein students
constantly modify their work until satisfied with the result. Although
this group used a very thoughtful and detailed process by which it found
the solution, it is not reflected in the product. Their product was acceptable
but with revision could be classified noteworthy. They gave the dimensions
that the bag would need to be, omitting the measurement of the length
of the bag. This group began with an area model and built it to be a volume
model. No discussion of this or any of the measurements of the money appeared
in the written product. The group members stated that the volume of the
bag would be too great for one robber to carry and alluded to the fact
that a bag of that volume would also be too heavy to carry. However, they
did not justify their hypothesis about weight.
GROUP
4'S INCLUSION-GROUP RESULTS After struggling to get started, group 4's
students disagreed on procedure. For example, Jerry (students' names are
pseudonyms) attempted to take charge and to convince everyone of his ideas.
Jerry usually lacks confidence and is reluctant to initiate conjectures,
but in this task he participated enthusiastically. He believed that the
size of the money did not matter and that the group should concentrate
on the weight. Isaac, however, believed that the model money had to be
the exact size. Eventually, the group members decided to work together
to make models of the entire $1 million. Their representations were arbitrary
in size, and they used the calculator to total their stacks of "money."
They marked the bills as $1, $5, and $10 in sequence to simulate an equal
distribution of small denominations. They also included several large
bills, since they reasoned that since "most" of the bills were in small
denominations, some large bills could be included as well. It is significant
that this group was highly motivated to pay careful attention to the details
of the given information, since these students typically have trouble
understanding written communication. They were determined to produce a
reliable and convincing product.
Katie
was absent the day that the problem was presented. When she returned,
she found it hard to accept her group's ideas. She thought it sufficient
to just measure a dollar bill, figure out the number of bills needed,
and see what size bag would hold this amount. She concentrated on bag
dimensions, but considered only width, not an area model. She insisted
on working alone, confidently completing her product quickly. Her report
needed "major revision." Although attempting to support her ideas using
actual computation is a good approach, she needed to explain clearly where
she got her numbers to justify her theory.
Ultimately, other group members decided not to hand in one collaborative
product because of their disagreements. These students all have substantial
language deficits, making it a taxing chore for each to produce written
work. They each made a concerted effort to provide details in their individual
products to make their reports more convincing. Jerry worked alone to
prepare his product and created the most convenient scenario to conform
with this hypothesis, assuming that one bill could be worth $500 000 and
another worth $1 000. He reasoned that any large bill would weigh the
same amount as a small bill and, therefore, even if the rest of the money
were in small denominations, the money would not be too heavy to be carried
by one person. His work needs "major revision." To be convincing, his
argument should have contained a breakdown of the number of bills that
would comprise the $1000 000. In addition, using weight in his argument,
he should have discussed the number of pounds that the money would weigh.
Roger
and William worked together and logically explained their conclusion,
although they used the words pound and ounces interchangeably. They weighed
the bills on a scale and determined that about thirty bills weighed an
ounce. They knew that sixteen ounces are in a pound and were able to use
this information to multiply 30 by 16 accurately to conclude that a pound
of bills would contain about 480 bills. They then divided 480 by 1 000
000 to find the weight of 1 000 000 bills, making two distinct mathematical
errors. They misinterpreted their calculator results because they had
limited experience with technology and they confused the divisor and the
dividend. Misled by this error, they believed that 1 000 000 bills would
weigh 48 pounds instead of 2 083 pounds, and did not consider whether
this result was reasonable. Their work needed minor revision; they did
an admirable job of thinking through the problem and devising a sound
plan to find a solution.
Isaac
decided that only $2 000 of the money had to have been in ones, fives,
and tens and the rest could have been in large bills. His work needed
redirection in that he apparently did not understand that $2000 was not
most of the money. This misconception reveals a weakness in number sense,
as he did not seem to understand the value of the number 1000 000.
CONCLUSIONS
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FIGURE
1 SUMMARIZES THE group's work. The dissent observed in group 4 is positive.
Although they participated in group discussions, none of these students
wanted to concede to one another; each believed in her or his own process
and solution. This modified-curriculum group was able to function well
in this setting for this activity. At times, students from this group
competently mingled with other groups to discuss issues related to the
problem.
Group
2 called on Katie for help when she had handed in her product, and Jerry
discussed his ideas with other students before class. The support of their
regular teacher encouraged them to conduct discussions about their ideas
within the group. In so doing, they extended their knowledge and became
more confident in justifying their problem-solving strategies within the
larger community.
The
week after the problem was completed, Tarlow conducted informal interviews
with her students. After the project was completed, Jerry discussed the
problem with his private tutor. The tutor told him that his solution was
wrong and spent a great deal of time explaining the "correct" solution
in detail. Jerry was unable to relate anything about the tutor's solution
to Tarlow. He still believed in his own product and was able to recall
every detail of his work, which confirms that students who construct and
take ownership of knowledge retain and can apply it. Katie said that she
enjoyed the task because she thought that she had done "good work." Isaac
liked the task because it was "a very thinking problem."
The
students in the modified-curriculum group expressed their desire to do
other Packets problems that involve creating products for clients. To
see whether these students could apply what they had learned, they were
told that a fourth-grade class was trying to collect 1 000 000 soda-can
tabs. They were told that in six weeks the students in the fourth-grade
class had already amassed 1 000 tabs and believed that they would reach
their goal by the end of the school year. Group 4 recognized the enormity
of the task and protested the unreasonableness of the expectation. Jerry
immediately and vehemently stated, "One hundred percent they can't do
it by the end of the year; 1 000 isn't even close to 1 000 000," indicating
increased number sense as a direct result of working on this problem.
In
general, students' oral explanations were far superior to their written
work. Several supportive details omitted in writing were clearly expressed
verbally, which reinforces the importance of using different means to
assess students' understanding. Therefore, teacher observations became
an integral part of assessing students' solutions. This situation raises
two issues: (1) it is crucial that the teacher observe carefully what
processes the students use to solve the problems and encourage them to
explain their work as they strive toward a solution and (2) students need
to be given the opportunity to discuss their written products, to be questioned
about them, and to make revisions that will reflect the thoroughness of
their work. Every group demonstrated a need to map the concepts to concrete
models, such as by cutting out and labeling bills.
Students
were motivated by the problem. They remained on task through several class
periods and continued to discuss related issues outside of class, during
recess, and after school. They eagerly anticipated continuing their work.
Although the students did an admirable job with the problem, discussion
and revisions are still needed. Students need an opportunity to share
their products with other groups, to rethink their ideas, and to make
revisions. The big ideas in this problem will continue to be explored
in other contexts; after that, the problem can be revisited.
ADDED
MATERIAL
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Educational
Testing Services. PACKETS Performance Assessment for Middle School Mathematics
Teacher's Program Guide. Boston, Mass.: D. C. Heath & Co., 1995.
National
Council of Teachers of Mathematics (NCTM). Curriculum and Evaluation Standards
for School Mathematics. Reston, Va.: NCTM, 1989.
Papert,
Seymour. Mindstorms: Children, Computers, and Powerful Ideas. New York:
HarperCollins Publishers, 1980.
Project
RISE. "International Perspectives on Inclusion." Program presented at
the annual conference sponsored by the College of Education at the University
of Memphis, Memphis, Tenn., October 1997.
Wingert,
Pat. "The Sum of Mediocrity." Newsweek 23, 2 December 1966, 96.
SOURCE:
Mathematics Teaching in the Middle School 4 no7 478-83 Ap '99. Reproduced
with permission from Mathematics Teaching in the Middle School, copyright
1999 by the National Council of Teachers of Mathematics. All rights reserved.
AUTHOR:
SYLVIA A. BULGAR AND LYNN D.TARLOW
SYLVIA
BULGAR, SBulgar@aol.com, is a mathematics curriculum coordinator and teacher
in Piscataway, New Jersey. She is a doctoral student in mathematics education
at Rutgers University, New Brunswick, NJ 08903. Her professional interests
include teacher development and the use of problem solving as an assessment
tool.
LYNN
TARLOW, LTarlow@bigfoot.com, is a mathematics curriculum coordinator and
teacher in Brooklyn, New York, and has taught all levels of mathematics,
including special programs for gifted students and for students with learning
disabilities. She is completing her doctorate in mathematics education
at Rutgers University, New Brunswick, NJ 08903. Her professional interests
include children's construction of mathematical ideas and teacher-development
reform.
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