CHAPTER XXIII

EXPERIENCES OF MATHEMATICAL TRUTHS

By means of toys, handwork and games, as well as various private

individual experiments, a child touches on most sides of mathematics in

the nursery class. In experimenting with bricks he must of necessity

have considered relative size, balance and adjustment, form and

symmetry; in fitting them back into their boxes some of the most

difficult problems of cubic content; in weighing out "pretence" sugar

and butter by means of sand and clay new problems are there for

consideration; in making a paper-house questions of measurement evolve.

This is all in the incidental play of the Nursery School, and yet we

might say that a child thus occupied is learning mathematics more than

anything else. Here, if he remained till six, he did a certain amount of

necessary counting, and he may have acquired skill in recognising

groups, he may have unconsciously and incidentally performed

achievements in the four rules, but never, of course, in any shortened

or technical form. Probably he knows some figures. It is best to give

these to a child when he asks for or needs them, as in the case of

records of games. On the other hand he may be content with strokes.

Various mathematical relationships are made clear in his games or trials

of strength, such as distance in relation to time or strength, weight in

relation to power and to balance, length and breadth in relation to

materials, value of material in relation to money or work. By means of

many of his toys the properties of solids have become working knowledge

to him. Here, then, is our starting-point for the transition period.

AFTER THE NURSERY STAGE

Undoubtedly the aim of the transition class is partly to continue by

means of games and dramatic play the kind of knowledge gained in the

Nursery School; but it has also the task of beginning to organise such

knowledge, as the grouping into tens and hundreds. This organisation of

raw material and the presenting of shortened processes, as occur in the

first four rules, forms the work also of the junior school. To give to a

child shortened processes which he would be very unlikely to discover in

less than a lifetime, is simply giving him the experience of the race,

as primitive man did to his son. But the important point is to decide

when a child's discovery should end and the teacher's demonstration

begin.

This is the period when we are accustomed to speak of beginning

"abstract" work; it is well to be clear what it means, and how it stands

related to a child's need for experience. When we leave the problems of

life, such as shopping, keeping records of games and making measurements

for construction; and when we begin to work with pure number, we are

said to be dealing with the abstract. Formerly dealing with pure number

was called "simple," and dealing with actual things, such as money and

measures, "compound," and they were taken in this order. But experience

has reversed the process, and a child comes to see the need of abstract

practice when he finds he is not quick enough or accurate enough, or his

setting out seems clumsy, in actual problems. This was discussed at

greater length in the chapter on Play.

For instance, he might set down the points of a game by strokes, each

line representing a different opponent:

John ||||||||||||||||

Henry |||||||||||

Tom |||

He will see how difficult it is to estimate at a glance the exact score,

and how easy it is to be inaccurate. It seems the moment to show him

that the idea of grouping or enclosing a certain number, and always

keeping to the same grouping, is helpful:

John |||||||||| |||||| = 1 ten and 6 singles.

Henry |||||||||| | = 1 ten and 1 single.

Tom ||| = 3 singles.

After doing this a good many times he could be told that this is a

universal method, and he would doubtless enjoy the purely puzzle

pleasure in working long sums to perfect practice. This pleasure is very

common in children at this stage, but too often it comes to them merely

through being shown the "trick" of carrying tens. They have reached a

purely abstract point, but they cannot get through it without some more

material help. The following is an example of the kind of help that can

be given in getting clear the concept of the ten grouping and the

processes it involves:

[Illustration: Board with hooks, in ranks of nine, and rings]

The whole apparatus is a rectangular piece of wood about 3/4 of an inch

thick, and about 3x1-1/2 feet of surface. It is painted white, and the

horizontal bars are green, so that the divisions may be apparent at a

distance; it has perpendicular divisions breaking it up into three

columns, each of which contains rows of nine small dresser hooks. It can

be hung on an easel or supported by its own hinge on a table. Each of

the divisions represents a numerical grouping, the one on the right is

for singles or units, the central one for tens, and the left side one

for hundreds: the counters used are button moulds, dipped in red ink,

with small loops of string to hang on the hooks: it is easily seen by a

child that, after nine is reached, the units can no longer remain in

their division or "house," but must be gathered together into a bunch

(fastened by a safety pin) and fixed on one of the hooks of the middle

division.

Sums of two or three lines can thus be set out on the horizontal bars,

and in processes of addition the answer can be on the bottom line. It is

very easy, by this concrete means, to see the process in subtraction,

and indeed the whole difficulty of dealing with ten is made concrete.

The whole of a sum can be gone through on this board with the

button-moulds, and on boards and chalk with figures, side by side, thus

interpreting symbol by material; but the whole process is abstract.

The piece of apparatus is less abstract only in degree than the figures

on the blackboard, because neither represents real life or its problems:

in abstract working we are merely going off at a side issue for the sake

of practice, to make us more competent to deal with the economic affairs

of life. There is a place for sticks and counters, and there is a place

for money and measures, but they are not the same: the former represents

the abstract and the latter the concrete problem if used as in real

life: the bridge between the abstract and the concrete is largely the

work of the transition class and junior school, in respect of the

foundations of arithmetic known as the first four rules.

Games of skill, very thorough shopping or keeping a bankbook, or selling

tickets for tram or train, represent the kind of everyday problem that

should be the centre of the arithmetic work at this transition stage;

and out of the necessities of these problems the abstract and

semi-abstract work should come, but it should _never_ precede the real

work. A real purpose should underlie it all, a purpose that is apparent

and stimulating enough to produce willing practice. A child will do much

to be a good shopkeeper, a good tram conductor, a good banker; he will

always play the game for all it is worth.

The child under eight · 第 11 / 15 章