Problem Solving

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Problem Solving

• Lecture Notes 9-17-08
• EDEL 473 Math Methods for Elementary Teachers
• Kansas State University

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Skills are to mathematics what scales are to
music or spelling is to writing. The objective
of learning is to write, to play music, or to
solve problemsnot just to master skills.
Everybody Counts (1989)
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Math Standards

• Content Standards
• Number and Operations
• Algebra
• Geometry
• Measurement
• Data Analysis and Probability

• Process Standards
• Problem Solving
• Reasoning and Proof
• Communication
• Connections
• Representation

Three Types of PS
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Problem Solving Goals and Objectives

• Familiarize Students with P.S.
• The four step process
• Strategies for solving problems
• Communicating thinking involved in solution
  process
• Teacher Behaviors
• Knowledge of the problem
• Knowledge of potential solutions
• Engaging students in the P.S. process
• Guiding the process
• Assessing the students P.S. process

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Problem Solving Goals and Objectives

• 3. Student Behaviors
• Involvement in the PS process
• Knowledge of and identification of potential
  strategies for solving specific types of problems
• Application of knowledge and skills needed to
  find a solution
• Communicating and justifying the solution as well
  as the process used to arrive at the solution
• Appropriate use of knowledge and experience
  gained for future problem solving

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Problem Solving Setting the Stage

• Persistence
• Knowing when to change directions
• Knowing what questions to ask when obstacles are
  met
• Problem Selection (Enthusiasm)
• Relevant problems create enthusiasm for problem
  solving
• Enthusiasm on the part of a teacher translates to
  a positive disposition for students.
• Now thats an interesting problem, I wonder how
  we can find the answer.

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Problem Solving Setting the Stage
3. Strategies a) Acquiring a variety of
strategies is essential to experiencing
success. b) Students should be provided with
instruction and practice in using a wide range of
strategies upon which they can draw. c) When
students are presented with a problem that does
not fit into the context of what they already
know, they need to know how to develop strategies
based on previously learned skills and concepts.
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Problem Solving Sample
How much time have you spent watching TV in
your lifetime? Estimate the amount of
time you have spent watching television in your
life. Include video games played on the
television screen, too. Write a report that
explains how you approached the problem, the
figuring you did, and how you came up with your
estimate. What benefits are there to using
this type of problem with your students?
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Problem Solving
Problem solving is at the core of any
mathematics curriculum it is integral to all
mathematical activity. As such, it should
permeate the entire mathematics program. Students
who are consistently presented with challenging
problems learn to develop and apply new
strategies. When they are also given
opportunities to communicate their strategies
with others and reflect on their thinking, their
problem solving abilities are further enhanced.
(Fennell et al. 2000)
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Problem Solving Defined!
Problem Solving means engaging in a task for
which the solution method is not known in
advance. (NCTM, 2000) A problem is a
situation in which a person is seeking some goal
and for which a suitable course of action is not
immediately apparent. (Marilyn Burns, 2001)
Solving problems takes place when students think
flexibly, creatively, and analytically to define,
examine, diagnose, and unravel complicated
problems. There must be some blockage on the part
of the potential problem solver. That is a
mathematical task is a problem only if the
problem solver reaches a point where he or she
does not know how to proceed.
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Three Problem Solving Approaches

• Teaching for problem solving.
• Teaching about problem solving.
• Teaching via problem solving.

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Teaching for Problem Solving

• Uses real-life problems as a setting in which
  students can apply and practice recently taught
  concepts and skills.
• The painter mixed the green paint using a 2 to 5
  ratio of blue to yellow paint. How much yellow
  paint is there in 1 gallon of green paint.
• Traditional problem-solving experiences familiar
  to most adults.

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Teaching About Problem Solving

• Refers to instruction that focuses on strategies
  for solving problems
• Polya, 1954
• Four Step Method
• Heuristics
• Process vs. Procedure
• Critical Thinking
• Examples

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Pedagogical Approach to Problem Solving

• Four Step
• Process
• Understanding the problem
• Choosing a strategy
• 3. Implementing a strategy
• 4. Finding and reporting a solution

• Blooms
• Taxonomy
• Knowledge
• Comprehension
• Application
• Analysis
• Synthesis
• Evaluation

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The value of a tool is in its usefulness.
Being able to do pencil-paper computation will
not serve students without the ability to
interpret a problem, analyze what needs to be
done, and evaluate the solution.
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Step 1 Understanding the Problem

• Correctly identify the problem situation or the
  question which is being asked.
• What is known? What is missing?
• Is there any mathematical language being used
  which I dont understand?
• Could I use a diagram to help clarify the
  problem? Could I paraphrase the problem and
  summarize what is being asked in my own words?
• Can I determine what a reasonable answer might
  look like?
• Have I ever solved a similar problem?

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Dealing In Horses!
A man bought a horse for 50 and sold it for 60.
He then bought the horse back for 70 and sold it
again for 80. What do you think was the
financial outcome of these transactions?
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If the only tool you have is a hammer,
everything around you looks like a nail.

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Step 2 Choosing a Strategy

• Explore, identify, and choose a problem solving
  strategy.
• Can I identify a series of steps which are needed
  to solve the problem?
• Are there one or more sub-problems to solve? How
  can I organize data to assist in solving the
  problem?
• Is there more than one strategy which I could use
  to solve this problem?
• Does choosing one strategy over another make the
  implementation easier?

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Step 2 Choosing a Strategy

• Develop a model of the problem using a picture
• Make an organized list or a table
• Solve a simpler problem
• Guess and check
• Work backwards
• Look for a pattern
• Act out the problem
• Use concrete objects
• Draw on other strategies developed by the student

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Tug-O-War
Acrobats, Grandmas, and Ivan Round 1 On one side
are four acrobats, each of equal strength. On the
other side are five neighborhood grandmas, each
of equal strength. The result is dead even. Round
2 On one side is Ivan, a dog. Ivan is pitted
against two of the grandmas and one acrobat.
Again its a draw. Round 3 Ivan and three
grandmas are on one side, and the four acrobats
are on the other. Who will win the third round?
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Step 3 Implementing a Strategy

• Correctly implement the strategy you have chosen.
• What is the sequence of steps which I need to
  implement? Have I performed the required
  computations accurately?
• Have I shown an adequate amount of work to
  demonstrate which strategy I have used?
• Have I carefully checked steps where I have
  previously made mistakes before?
• Would choosing an alternative strategy make the
  solution process easier?

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Frozen Yogurt A Manager who operates a
frozen yogurt shop has a vending machine with
three buttons. When these buttons are pushed,
each one dispenses a different flavor of frozen
yogurt. One of the buttons dispenses chocolate,
another button dispenses vanilla, and the another
button dispenses todays special. When the shop
operator is extremely rushed, the manager uses
chocolate or vanilla as the special. Suppose it
is a hectic day, all the buttons are mislabeled,
and the manager offers you a free carton of
yogurt if you can push one button and determine
how to correct all the labels. Which button would
you push?
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Step 4 Finding and Reporting a Solution

• Find and report a conclusion from the strategy
  you implemented.
• Is my solution reasonable and does it solve the
  problem according to my understanding?
• Can I check or verify my solution by substituting
  the results from the original problem?
• Do I need to reinvestigate the appropriateness of
  my problem solving strategy?
• Does my solution make sense? Is it reasonable? Is
  my conclusion similar to what I predicted
  earlier?

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• Kansas Resources
• Mr. Allens Kansas History Class was
  working in groups to do research on Kansas
  history. The numbers below reflect the number of
  resources each group used.
• 5, 7, 10, 5, 14, 12, 7, 13, 5, 12
• Which statement is true for the given set of
  data?
• The mean is less than the median.
• The mode is less than the median.
• The mode equals the mean.
• The range equals the sum.

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Recommendations for Teaching About Problem Solving

• Heuristics
• Strategies taught in isolation are not meaningful
  to students.
• Allow students to identify or create meaningful
  solution strategies.
• Post strategies and refer to them often.
• Demonstrate the need to draw upon a wide variety
  of solutions strategies.
• Be selective with problems less is more
  quality over quantity

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Sure-Fire Rules For Problem Solving

• Most problems are addition.

2. If more than two numbers are given, it has
to be addition.

• When only two numbers are given and they are
  about the same
• subtract.

4. Consider subtraction when money is involved,
particularly if one amount is a round
figure like 50 or 10.00.

• If two numbers are given and one is much larger
  than the other,
• try division.

• Very few problems involve division with a
  remainder. When you
• get a remainder, cross out the division
  and multiply instead.

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Sure-Fire Rules For Problem Solving
7. If you see a fraction, invert it.
8. If you see a decimal, move it.
9. If you see a negative or positive sign, change
it.
10. If the Rules 1-9 do not seem to work, make
one last desperate attempt. Take the set of
numbers in the problem and perform about
two pages of random operations using these
numbers. You should circle about five or
six answers on each page just in case one
of them happens to be the answer. You might get
some partial credit for trying hard.

• Never, never spend too much time solving
  problems. This set of
• rules will get you through even the longest
  assignment in no
• more than 10 minutes with very little
  thinking!