Problem solving What is problem solving? Weak and strong methods. Weak methods of problem solving.
Problem solving secondary
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Transcript of Problem solving secondary
A Problem Solving Approach to the teaching of Mathematics at the
Secondary level
Developing Habits of Mind
Judith SediDavion Leslie
Objectives
To explore the features of problems
To establish a framework for developing
problem solving skills in students.
To explore the benefits of adopting a
problem solving approach to teaching
math.
Have you ever met students who
can perform operations and algorithms but are unaware of
what they are doing?
slavishly follow algorithms regardless of what they are
doing?
cannot respond to context based questions – even though
they can perform the operations implied in the questions?
require an example before they can ‘solve a problem’
are not able to try different approaches in order to arrive at
a correct answer?
Thinking-based curriculum
Thinking based curriculum
What is the thinking based curriculum?
How can it address some of the problems
mentioned before?
What is the true purpose of teaching math in
school?
Does what exists now in schools qualify as the
thinking based curriculum?
What is a Problem ?
Any task or activity for which the
students have no prescribed or
memorized rules or methods, nor is
there a perception by students that
there is a specific ‘correct’ solution
method (Hiebert et al. , 1997)
What is a Problem ?We can safely say that most worded
“problems” are simply “dressed up
algorithms”, exercises that give prompts by
using specific words such as “altogether”,
“shared among” and students do them
without truly understanding what the
question is about.
“Problems that are truly problematic do not
have clear or single solution paths”
(Schoenfeld, 1985, p. 34).
“Computational exercises for which students
do not have a readily-accessible method or
approach can be truly problematic” (Yackel,
Cobb and Wood, 1988, p. 87).
Problem solving
Problems are not to be seen as traditional word
problems.
Traditional word problems “provide contexts for
using particular formulas or algorithms but do not
offer opportunities for true problem solving”
(NCTM, 1989, p. 76).
Problems are, therefore, NOT contextualised
algorithms
According to NCTM
Benefits of Problem solving It develops students’ higher order thinking skills
It allows the student the opportunity to express
their understanding of the concept
It reduces dependence on memory
It creates multi-dimensional classroom setting
It caters to the multiple intelligences of children
Developing problem solving skillsThe aim of mathematics teaching is not to make
students solve problems but to make them into
problem solvers.
Lessons should not only expose students to
problems but also develop the habits of mind that
enable them to become problem solvers.
Students must be made to see an activity as an
opportunity to think and not a question to be
unpacked with and through algorithms.
Developing habits of mindIntroductory problem
A tournament is being arranged among 22 teams.
The competition will be on a league basis, where
every team will play each other twice – once at
home and once away. The organizer wants to know
how many matches will be involved.
Habits of mindAt first the problem appears difficult
No known algorithms exist and students may not
have an example of a similar problem.
Students may not know how to approach the
problem.
How would you intervene at this stage?
What would you say?
Would you give an example?
Would you model an approach?
Would you do anything at all?
Habits of mindHow do we start?
How about simplifying the problem?
Suppose instead of 22 teams, there were only 4?
But still, how do we start?
Well figure out a system for recording how many
matches 4 teams will play.
Habits of mindAvoid this:
A v B
B v A
C V A
A v D
C v D
C v B
C v A
A v D
Be systematic and
organised like this:
A v B A v C A v D
B v A B v C B v D
C v A C v B C v D
D v A D v B D v
C
Randomly
listing
possible
matches
may cause
repetitions
and/or
omissions.
Habits of mindOr better yet, like this:
Habits of mindBy now you should realise that 4 teams will play
12 matches.
Does this mean that the number of matches will
be 3 times the number of teams?
Will 22 teams play 66 matches?
Perhaps we should try a few more cases to see.
Which cases would you try and why?
Habits of mindYou now know how many matches 3 – 6
teams will play.
It’s perhaps best to make a table to
capture your findings.
Teams 2 3 4 5
Matche
s
2 6 12 20
Habits of mindNow that you have a table, look for patterns.
Write down the patterns that your are observing
Look for horizontal (side to side) as well as vertical
(top down) patterns
Look for
Differences (1st and 2nd)
Relationships
Rules
Patterns such as symmetry, odd-even, number types, etc.
Habits of mindUse your patterns to solve the original
problems with 22 teams.
Which patterns/relationships are more
helpful – vertical or horizontal?
Can you find a general rule that tells you the
relationship between the number of teams
and the number of matches?
Can you make it into an algebraic
expression?
Habits of mindTry some simple cases
Find a helpful diagram/creating models
Organise systematically
Examine results (make a table, etc)
Spot patterns
Explore/use the patterns
Find a general rule
Some final thoughtsThe problem was stated with 22 teams; was
this number too small, too large or
challenging enough?
What information in the question would
require some explanations or background
information?
Is this best done as group work or as
individual work?
What could we change about the question to
create an extension/variation?
Habits of mindNow, in your groups, attempt problems 1 – 3
on the activity sheet.