
CMC
Infinity Wall  George Polya, 1887–1985
George Polya: The
Father of Problem Solving in Mathematics Education
In His Own Words— from
a lecture to teachers transcribed by Thomas C. O’Brien
George Polya can rightly be called the
father of problem solving in mathematics education. For that
distinction and his many contributions to our field, the California
Mathematics Council chose to name one of our prestigious awards in his
honor.
Dr. Polya
was a distinguished mathematician and professor at Stanford
University. Polya (1887–1985) made important contributions to
probability theory, number theory, the theory of functions, and the
calculus of variations. He was the author of the classic works How to
Solve It, Mathematics and Plausible Reasoning, and Mathematical
Discovery, which encouraged students to become thoughtful and
independent problem solvers. He was an honorary member of the Hungarian
Academy, the London Mathematical Society, and the Swiss Mathematical
Society, and a member of the (American) National Academy of Sciences,
the American Academy of Arts and Sciences, and the California
Mathematics Council, as well as a corresponding member of the Academie
des Sciences in Paris. The firstperson essay that follows is a slightly edited transcript of
a lecture Professor Polya presented to Tom O’Brien’s inservice and
preservice mathematics education students in the late 1960s. There is
no better way to understand the problem solving philosophy George Polya
so strongly advocated for students, then to read his own words:
I wish to talk to you about the
teaching of mathematics in the elementary school. In fact my talk will
consist of two parts. In the first part I will talk about the aims of
teaching mathematics in the elementary school, and in the second part,
how to teach it.
I must confess that I am talking about these things as an outsider. I
was always interested in teaching, but most of my time, about half a
century, I taught in the university, and in the last fifteen years, I
was mainly concerned with teaching on the high school level. Thus I am
talking to you as an outsider, but you may find one or two points in
what I am saying that may be useful to you in your grade level.
What is the aim of teaching mathematics in the elementary school? It is
better to consider the most general question: What is the aim of the
schools? And the even better question is: What do people generally
think is the aim of the schools? The first is the point of view of the
parents. Your neighbor Mr. Smith has a son Jimmy. He is against Jimmy
being a dropout. He says that if Jimmy drops out of school he will
never get a good job. So the aim of the school, according to Mr. Smith
and all the other Mr. and Mrs. Smiths in the general public, is to
prepare Jimmy for a job—to prepare students to earn a living. But what
is the point of view of the community? It is the same. The community,
the country, the state, and the city all want people to earn a living
and pay taxes and not live on public assistance. So the community also
wants schools to prepare young people to have jobs.
If the parents think a little farther, and the community thinks a
little farther, the aim is somewhat different. Reasonable parents, a
reasonable Mr. and Mrs. Smith, want their son Jimmy to have a job for
which he is well suited so he will earn more and feel happier. By the
way, this is also the aim of the community—that you have jobs on one
side and people on the other side, and you assign people to jobs they
are best suited so that they produce the greatest output. Or even
better, their happiness should be maximized.
What can the school do for that? The point is that when a child comes
to school you can’t know what job he or she will have later on, nor do
you know what job he or she will be best suited. So what should we do?
We should prepare youngsters so they can choose between ALL possible
jobs, and give them a view of the whole world so they can recognize
which jobs will best suite them. You can express this in many ways. I
like the following: Schools should develop all the interior resources
of the child.
We have therefore two kinds of aims in the schools. We have good and
narrow aims—schools should turn out employable adults who can fill a
job. But a higher aim is to develop all the resources of growing
children so they can fill the job for which they are best suited. The
higher aim is to develop all the inner resources of the child.
Now what about mathematics teaching? Mathematics in the elementary
schools has a good and narrow aim, and that is pretty clear. Everybody
should be able to read and write and do some arithmetic, and perhaps a
little more—an adult who is illiterate is not employable in a modern
society. Therefore the good and narrow aim of the elementary school is
to teach the arithmetical skills—addition, subtraction, multiplication,
division, how to measure length, area, volume, fractions, percentages,
rates, and perhaps even a little more. This is a good and narrow aim of
the elementary schools—to transmit this knowledge—and we shouldn’t
forget it.
However, we must also have a higher aim if we wish to develop all the
resources of the growing child. And the part that mathematics plays is
mostly about thinking. Mathematics is a good for teaching thinking. But
what is thinking? The thinking that you can learn in mathematics is,
for instance, to handle abstractions. Mathematics is about numbers.
Numbers are an abstraction. When we solve a practical problem, in order
to solve this, we must first make it into an abstract problem.
Mathematics applies directly to abstractions. Some mathematics teaching
should at least enable a child to handle abstractions, to handle
abstract structures. Structure is a fashionable word now. It is not a
bad word. I am quite for it.
But I think there is one point that is even more important:
Mathematics, you see, is not a spectator sport. To understand
mathematics means to be able to do mathematics. And what does it mean
doing mathematics? In the first place it means to be able to solve
mathematical problems. To achieve the higher aims I am talking about,
there are some general tactics of problem solving—the right attitude
for problem solving and ability to attack all kinds of problems, not
only simple problems that can be solved with simple arithmetic, but
more complicated problems of engineering, physics and so on, which will
be further developed in the high school. But the foundations of problem
solving should be started in the elementary school. And so I think an
essential point in the elementary school is to introduce children to
the tactics of problem solving—not to solve this or that kind of
problem, not to make just long divisions or some such thing, but to
develop a general attitude and ability for the solution of problems.
PART II
Teaching is not a science; it is an art. If teaching were a science
there would be a best way of teaching and everyone would have to teach
like that. Since teaching is not a science, there is great latitude and
much possibility for personal differences. In an old British manual
there was the following sentence, “Whatever the subject, what the
teacher really teaches is himself.” So therefore when I tell you to
teach so or so, please take it in the right spirit. Take as much of my
advice as fits you personally. You must teach yourself.
George Polya’s Advice to
Teachers:
 Be
interested in your subject.
 Know your subject.
 Know about the ways of learning: The best way to
learn anything is to discover it by yourself.
 Try to read the faces of your students, try to see
their expectations and difficulties, put yourself in their place.
 Give them not only information, but "knowhow,"
attitudes of mind, the habit of methodical work.
 Let them learn guessing.
 Let them learn proving.
 Look out for such features of the problem at hand as
may be useful in solving the problems to come  try to disclose the
general pattern that lies behind the present concrete situation.
 Do not give away your whole secret at once  let the
students guess before you tell it  let them find out by themselves as
much as is feasible.
 Suggest it,
do
not force it down their throats.
There
are as many good ways of teaching as there are good teachers. But let
me tell you my idea of good teaching. Perhaps the first point, which is
widely accepted, is that teaching must be active, or rather learning
must active—this is the better expression.
You cannot learn just by reading. You cannot learn just by listening to
lectures. You cannot learn just by watching. We all must add the action
of your own mind in order to learn something. Socrates expressed it two
thousand years ago very colorfully when he said that an idea should be
born in the student’s mind, and the teacher should just act as a
midwife. The idea should be born in the student’s mind naturally and
the midwife shouldn’t interfere too much, too early. But if the labor
of birth is too long, the midwife must then intervene. This is a very
old principle and there is a modern name for it—discovery learning. The
student learns by his own actions. The most important action of
learning is to discover something by yourself. This should be the most
important part in teaching because what students discover by themselves
will last longer and be better understood.
There are other principles of teaching, or rules of thumb. Another
principle was stated by the great educators Socrates, Plato, Comenius,
and Montessori—that there are certain priorities in learning. For
instance, things come before words. Kant said, “All human cognition
begins with intuitions, proceeds hence to conceptions, and ends in
ideas.” Let me translate this into simpler terms. Learning begins with
action and perception, proceeds hence to words and concepts, and should
end in good mental habits. This is the general aim of mathematics
teaching—to develop in each student as much as possible the good mental
habits for tackling any kind of problem.
You should develop the whole personality of the student, and
mathematics teaching should especially develop thinking, clarity, and
persistence. It could also develop character to some extent, but most
important is the development of thinking.
I believe the most important part of thinking that is developed in
mathematics is the right attitude in tackling and solving problems. We
have problems in everyday life. We have problems in science. We have
problems in politics. We have problems everywhere. The right attitude
for problem solving may be slightly different from one domain to
another, but we have only one head, and therefore it is natural that
there should be one general set of tactics to tackling all kinds of
problems. My personal opinion is that the main point in mathematics
teaching is to develop these tactics of problem solving.
The two principles of active learning—priority of action and
perception—are taken into account by almost all mathematics teaching
today. However, there is allegedly a Chinese proverb that says, “I hear
and I forget. I see and I remember. I do and I understand.” So “I hear
and I forget.” What you just hear you forget quickly. Good advice is
very quickly forgotten. What you see with your own eyes is remembered
better, but you really understand it when you do it with your own
hands. So there must be more than just priority of action and
perception in our teaching.
Therefore the schools, especially elementary schools, are today in an
evolution. A sizable fraction, ten to twenty percent, already have the
new method of teaching which can be characterized in the following way
compared with the old method of teaching. The old method is
authoritative and teachercentered. The new method is studentcentered.
In the old time the teacher was in the center of the class or in front
of the class. Everybody looked at the teacher and what he or she said.
Today the individual students should be in the center of the class, and
they should be allowed to do whatever good idea comes to their mind.
They should be allowed to pursue ideas in their own way, each by
themselves, or in small groups. If a student has a good idea in a class
discussion then the teacher changes his plans and allows the class to
follow this good idea.
I must tell you one name, a person who is particularly active in this
direction and who is very clever, very good. This is Miss Edith Biggs.
She is a particularly gifted teacher who stands in with great
enthusiasm and talent for this new studentcentered teaching.
In such a studentcentered class, each group of kids are doing
something else. They play (let’s just say that they think that they
play, but really they learn). The teacher gives them various materials.
A class period consists of the teacher giving kids various materials
and a problem to solve. They play and they develop their own ideas in
play. For instance, one of the materials is squared paper. And a good
supply of cubes, cubes of one half inch and several dozens of them,
maybe even a hundred. So the kids play with that. It is activity
teaching—teaching by action involvement.
Let me give you an example of this activity. The class discusses little
rectangles—proceeding from action and perception of things they have
often seen and touched. Everybody has seen a room, and the walls of an
ordinary room are rectangles, or almost rectangles. So you naturally
learn what a rectangle is. The floor of the usual room is a rectangle.
And any wall is a rectangle. The ceiling is a rectangle. One key idea
in mathematics is to understand length and area, so you measure the
length of the rectangles and come to the concept of the perimeter of
rectangles. Then you deal with the area of the rectangle. You build up
the rectangle from equal squares, from unit squares, and come to the
notion of the area of rectangles.
We are now in a
class that is somewhat familiar with the area and
perimeter of rectangles. On the same sheet of paper, draw overlapping
rectangles, with the same perimeter—a perimeter of twenty (see
illustration below). There are nine such rectangles.
They start with width = 1 and height = 9, and then width = 2 and height
= 8, and down to width = 9 and height =1.
There are many things to observe—action and perception. Some of the
kids will be struck by the observation that all the corners of these
rectangles are on a straight line. Then they will notice that one of
these rectangles has equal sides and you can ask many questions about
it. One of the interesting points is that the teacher should not ask
the questions; the kids should ask the questions. They all have the
same perimeter. Do they have the same area? Which one has the greatest
area?
Here is another
activity with rectangles. Again take square grid paper
and cut out different rectangles, but this time with the same
areas—let’s say area of 24 square units. Overlap them on the same
paper. Now the corners opposite to the one corner in which they overlap
are not on a straight line. There is some funny kind of curved line.
Kids with an imagination will join these to make a curved line. So that
is another consideration. This is an example of an activity with
rectangles where the kids have their own choice. They make their own
remarks and the teacher just helps a little now and then with some
hints. If the kids have no ideas at all, then the wellinstructed
teacher, who is used to this studentcentered teaching, can give a few
good hints.
Perhaps one point that Miss Biggs and the Nuffield Foundation do not
emphasize sufficiently is the rule of guessing. Guessing comes to us
naturally. Everybody tries to guess and does not have to be taught to
do so. What has to be taught is reasonable guessing, and especially to
not believe your own guesses, but to test them. And students’ activity
will start much better if you start them by guessing.
Here is one example. One activity is to measure the length and the
width of the classroom. Some students may be bored by this if they have
already done it with a former teacher. You can get a little more
interest if you start with a guess. You may say, “It seems to me that
this classroom is twice as long as it is wide. Is it really?” I hope
some of the kids will say, “No, it is longer than twice.” Others will
say, “No, it is shorter.” A very few will say, “Exactly.” After they
have all guessed, they will do the measuring with much more interest
because everybody will be interested whether his or her guess will be
true or not. This is a very special case in the tactics of problem
solving. If you go farther, you will notice that guessing plays an
important role. The solution to a problem naturally always starts with
a guess, but not always with a good guess. On the contrary, usually the
guess is never completely good. It is just a little out of center and
the art of problem solving consists in great part in correcting your
guesses.
I have given you my ideas about how you should teach mathematics. They
are the ideas of active learning, priority of action and perception,
and teaching by allowing students to start an activity by letting them
guess. I hope one of these points will find a sympathetic ear with some
of you.
Thank you.

