EXERCISE.—Ask
a class of children to make up
some arithmetic problems
about the things that most interest them. Compare these problems with
those
found in the textbook.
Try to secure statements from your friends of
middle age as to the
value to them of the mathematics they studied in the elementary or the
secondary school. How, if at all, would they change the character or
amount of
instruction there?
The value of mathematics
to the world at large.—It
would be hard to overstate the importance of mathematics.
Our calendar expresses it, historical events are set in order by it,
every
natural science mounts by it, all
industrial arts are
wedded to it. Theorist or practitioner, no one can escape it. Nor does
our
little world bound it. Other worlds may
easily have
different history, different botany, different psychology,
different
literature from ours, but it is next to impossible to conceive of
their having
any mathematics different from ours.
Yet despite this apparently universal truth
and utility, there is but
slight demand, in the daily lives of most of us, for anything more than
the
merest rudiments of number and quantity. They are few who do not need a
modicum
of mathematics, but they also are few who need anything more.
Of course, we all profit by the genius of the
expert mathematician as
we do by the devotion of the expert physician, but that is no reason
for
becoming either kind of expert unless our "call" takes us that way.
Nature of mathematics.—Mathematics
is a kind of science. In beginning the study of it, we should make many
observations of the world about us, as we do in other sciences.
But the
peculiarity of mathematics is, that we so
quickly pass
on from the "observing" stage to the "reasoning" stage.
Its generalizations, some of which are called axioms, form the
foundation of a
great mass of deductions which make up the bulk of the science. It is
"the" deductive science.
Mathematics, then, has few (observed) facts
to remember, —no such
burden of them as we find in geography, botany, or chemistry. It is a
thinker's
paradise, for a certain kind of thinker.
Educational value of
mathematics.--In
some quarters it is still necessary to dispel the delusion that each
branch of
study has some peculiar mental power to develop. The truth seems to be
that any
branch of study can be so taught that it will train any mental power to
act on
that kind of subject matter, but not, usually, on all kinds. Thus
mathematics
develops, in one who has the "gift" for it, mathematical observation,
mathematical memory, mathematical imagination, judgment,
reasoning, feeling.
But it cannot of itself develop the power to
reason well on all
subjects. "It is more than doubtful . . . whether the severe study of
arithmetic would make any material difference in a man's capacity, as a
juryman, to draw sound conclusions from a tangled mass of evidence, or
as a
citizen, to trace admitted governmental evils to their source. . .
Facility in
the one kind of reasoning is no more a guaranty of facility in the
other than
is proficiency in playing golf or proficiency in playing chess." The general truth of this statement has been
borne out by the recent developments of experimental pedagogy.
Our chief aim in teaching mathematics to
children is to enable them to
solve the problems of everyday life, as those problems appear in the
household,
the market, and the shop. If we accomplish this aim, "discipline" and
"culture" will take care of themselves.
This means that it is the art of mathematics,
rather than the science,
that we are trying to impart. We should not care, until the child
himself
naturally desires to understand, whether he can "explain" his
addition and long division, his fractional and other operations, or
not. But we
should care constantly that he perform
these
operations with speed and accuracy. In other words the early lessons in
mathematics
should not be "thought lessons" only, but observation lessons,
information lessons, and especially lessons for skill. We are too much
afraid
of letting our children imitate us in mathematical operations, as
they do in
skating and shooting marbles. Even problem solving is partly habit.
In addition to this very practical reason for
teaching a little
mathematics to everybody, there is a special reason for teaching a
great deal
of mathematics to the limited number who have
strong
talent for it; it will serve them in their vocations as engineers,
architects,
investigators. So far as possible, we should teach mathematics to each
child in
accordance with what he is likely to do with it. One gains merely the
art of
reckoning, another glimpses the science of number, a third proves to
have been
born to further the cause of mathematics in the world. Vocation
determines the
value.
Subject matter.—More and more the principle prevails that subject
matter
shall be selected according to the needs of the pupils. "What can we
leave
out?" is the common question, and rightly. We are leaving out of
arithmetic such subjects as obsolete or little-used measures and
tables,
unusually intricate or lengthy problems, progressions, series,
compound
proportion, annuities, cube root, and many other subjects. At the same time the stress is ever more and
more on the applications of such topics as are taught, to practical
problems—pupils' problems.
From secondary-school algebra we find disappearing
the more elaborate method of finding the highest common factor,
difficult
simultaneous quadratics, all equations beyond the second degree, and
other
labored and little used topics.
Any
principle, having been developed,
illustrated, and well drilled in,
should be given a wider range of application, represented
by circle A. A pupil who learns how to
get the volume
of a sphere can apply the
formula (roughly) to the earth, sun, or moon. The result is similar
with new
combinations of old things; a boy who knows the circumference of
his bicycle
wheel can tie a small flag to one of the spokes and measure the
distance
between home and school.
But it is quite wrong to suppose that we can
teach much geography or
history or any other subject merely by offering information problems in
that
subject when teaching arithmetic. This is much like wearing skates
when
learning to dance, so as to master both skating and dancing by a single
effort.
A few may succeed in spite of the divided attention and effort.
General method in
mathematics.—Speaking
generally, there are but two kinds of work to master in mathematics.
They are:
- Fixed
operations, such as addition and
multiplication.
- Problems
to which these operations are
applied.
As stated before, many of the fixed
operations should be regarded as
acts of skill, learned chiefly by imitating the teacher, and left
unexplained.
This method should always be followed when the explanation proves to be
a
stumbling block, as in the case of division of fractions. Let us teach
practical doing, the art of calculating, whether we teach the elegant
science
of arithmetic or not.
When it seems likely that a class can get
some understanding of the
process to be taught, it may be approached as a problem to be solved.
The
following is suggested as a good type of general procedure.
(a) Let the new truth appear in the guise of
a problem. For instance,
when the class is ready to work out a rule for finding the area of a
rectangle,
we may propose the question, How can
we find the
number of squares in a checker board without counting them all?
(b) Let the pupils solve the problem under
the guidance and leadership
of the teacher. The work should be concrete and mainly oral. When a
rule or
principle is developed, a brief statement of it should be formulated
and
recorded. For example:
Area of rectangle = W x H.
(c) This terse statement should be fixed by
repetition and drilled upon
orally until it can be applied accurately and readily. Let it circulate
all
round the class.
(d) Fix the most desirable written form by
practice on board or paper,
the teacher carefully supervising.
(e) Let the pupils, as independently as may
be, apply the knowledge
gained to situations which to them are real and interesting problems.
2. The solution of particular problems may
proceed somewhat as follows:
(a) Image vividly the conditions of the
problem, drawing a figure or
picture if necessary, to aid.
(b) Discover just where or how the "answer"
must fit in with
the rest, and consequently how it can be obtained from the facts given.
(c) Translate the
language of the problem into
figures, and solve, writing no explanations except such as are
necessary to
aid the solver himself.
(d) When the answer is obtained in figures,
state what it means in the
concrete terms of the problem.
Concerning analyses and explanations, so
often abused, Dr. Smith is
eminently quotable:
To require
that every applied
problem should be solved in steps is to encourage arithmetical
dawdling.
- To
split hairs on such questions of form as 9 x r5c or r5c x 9
is to get
away from the essential point
- To
require no analyses of the
applied
problems is an extreme that is about as bad as to require them for all,
and
perhaps worse.
To require some particular form of analysis,
only to meet the idiosyncrasy
of the teacher, is also a danger against which we need to be on our
guard. . .
. In general, therefore, the teacher should see to it that there is a
reasonable
amount of rapid, accurate solution, the answers being the paramount
object. He
should see also that there is a reasonable amount of written analysis,
preferably in the convenient form of steps, but not limited in any
notional way
that would destroy originality or make a solution unnecessarily long."
Formal, detailed analysis should not be
required too early—say
before grade seven—but problems should be talked over and reasoned out
informally from the very be-ginning of school work.
The psychology of
arithmetic.—Fundamentally,
arithmetic is counting up and down the
number scale, with the invention of such short cuts as addition,
division,
etc., to quicken the process. Whatever the adult may make of his
concept of
number when he analyzes it, there is little doubt as to how the child
gets hold
of the idea. Out of the "blooming, buzzing confusion" that
surrounds
the young child, there comes home to him very early the consciousness
of changes, and particularly those
rhythmical changes that
readily form series. This series idea is built up from many sources,
breathing,
running, the clock tick, the drum, the
accented notes
in music.
The series idea is the basis
of the number
concept.
The series need not be named at first. The
essential thing is that it
should be abstracted, that is, separated from any particular concrete
objects
or events that have helped to build it up. This abstract series idea
can then
be applied in a manner that seems very much like counting, as in the
case of
the child who reproduces the strokes of the clock without using number
names,
saying, for example, "Boom! boom! boom!" when the clock strikes three.
Next comes the learning of the number names.
The first
"counting" should not be applied to things, any more than one would
point to objects when repeating a Mother Goose rime. It is purely a
memory
drill on a series of names. It is important, then, that the numbers be
taught
in their natural order. Having now gained his abstract series idea
named with
the number names, he is ready to apply it. Care is necessary that the
number
names be not applied at random, or regarded as the names of certain
individuals. Phillips gives a case of a boy who counted his neighbor's
four
dogs as follows: "Tip is naught, Bob is one, Nero is two, and Dandie is three."
The pupil may now proceed to count all sorts
of things in which he is
interested, using his fingers, the original basis of the "tens"
system, as freely as he chooses. Objects also find a large place in the
development of addition tables, etc., but the transition from things to
pictures of things and then to symbols purely, may follow rapidly.
FOR
FURTHER STUDY
- It is sometimes urged that
pupils should
write their problems,
because they must certainly think of the problem while they are writing
it. Is
this argument sound? Why?
- "Mathematics
teaches us to reason."
Discuss this pro and
con.
- State
the psychological reason for not
using, in the very beginning
of arithmetic, such general symbols as those employed in algebra.
- State,
in terms of habit, the reason why
children should not long
continue the use of objects in computation.
- Show
that all arithmetic can be reduced to
a matter of counting up
and down the number scale.
- Visit
some classes in mathematics, and try
to work out the
psychological reasons for the errors you find.
- What
use can be made of arithmetic in the
teaching of algebra?
- "Mathematical
study begets accuracy, the
prime requisite of the
truth teller, and so has a high moral value." Comment on this.
- Make a
list of those topics in arithmetic
for which you have found
frequent actual use since you left school.
- Discuss
"The use of imagery in
mathematical study."
- Should
models be used in the study of
geometry? Why?
- What
proportion of the work in arithmetic
should be oral? On what
do you base your answer?
- How
should you proceed with the boy who
counted, "Tip is
naught, Bob is one," etc.?