ations, is by no means so
valuable as _accuracy_;--and upon the above principle, it also follows,
that the person who acquires the greatest degree of accuracy and
confidence in working _addition_, must, of course, be most accurate in
all his calculations. The importance of this principle will be much more
prized by and bye than it can be at present;--we shall however shew here
how it may be taken advantage of.

Upon the principle of Individuation, we have seen, that a child will
learn one thing much better and sooner _by itself_, than when it is
mixed up with several others; and therefore we come to the conclusion,
that a child, when taught the practice of addition by itself, till he is
fully master of it, both as respects rapidity and accuracy, has
afterwards little more to do than to get a knowledge of rules. One
month's systematic exercise in _this way_, will do more in forming a
desirable accountant for a desk, than a whole year's exercise otherwise.
In the one case, the pupil starts to the race without preparation, and
with all his natural impediments clinging to him, which he has to
disentangle and throw off one by one during the fatigues and turmoil of
the contest; while the other, on the contrary, delays his start till he
has deliberately searched them out and cast them aside, and thus
prepared himself for the course. He then starts vigorous and light, to
outstrip his labouring and lumbering competitors, not only in this, but
in every after trial of strength and skill of a similar kind.

To follow out this plan with success, the "Arithmetic Rod," containing
three sides, has been provided. On one side there is a single line of
figures, on the second two, and on the third three. These lines of
figures for a school, ought to be painted on three boards sufficiently
large for all to see them distinctly. The first line is to be mastered
perfectly, before the second or the third is to be taught.

The way to begin with the first line, is to make the pupil mentally add
a certain sum to each figure on the board, say two, or seven, or
fourteen, or any other sum, beginning always with a small one. He is
besides to add the carryings also to each figure, and to write down the
sum as he goes on. The beginner may be exercised with the sum of two, or
even one, and have the sum increased, as he acquires a knowledge of the
method. These sums, as the pupils advance, may be extended to any
amount. The Key will shew, in every case,