Rock Island Argus. (Rock Island, Ill.) 1893-1920, 1896-10-09
SWIFT AT FIGURES.
EDUCATIONAL CIRCLES EXCITED OVER
LIGHTNING ARITHMETIC.

An Ohio Man Has . System which He
Thinks shssld h Taught In the scheoia
He Gives . Newspaper Man Some Illus
s~r.aions Of His Method.
Educational circles are in q pitch Of
excitement over the introduction in the
public schools of Chicago of a system of
instruction in what may be termed
lightning arithmetic. Many Of those
interested maintain that the proposition
is impracticable on the theory that only
such persons as have natural arithmet-
ical genius be able to use to advan-
tage any sort Of rapid calculation. The
incident and the attending interest led
a representative to make some inquiry
into whether or not there is any move
ment TO introduce the new system in
the schools Of this city. Although il is
the subject of not a little discussion
among the teachers Of the city, no steps
have as yet been taken.
One of the most interested in this city
is MI. q. D. Hinkle, who is connected
with the NJ. C. Lilley company. MI.
Hinkle has been in the mercantile bust
ness for a number Of years. much 81
which time has been spent in this city,
and has been regarded rs one Of the
most rapid calculators in the state. His
work has not been on the fancy order,
but straightforward use Of rapid meth
DDS in practical business. Having seen
Mr.. Hinkle add, subtract, divide and
multiply long lists of figures in billing
out goods of all sorts as fast ms his as
sistant could call them off to him, and
in 500 pages of ledger account having
made not n single mistake, The Dis.
patch was interested to know whether
the system mentioned in Chicago WINS
related in any way TO that which he
used.
Mr.. Hinkle was found mos. enthusi-
a~stically interested in tho method. and
quickly remarked, upon being asked.
that the supposed new system was iden-
tically the same that he has been using
for 25 years. Indeed, Mr.. Hinkle has
been for a number of years thinking Sc
riously Of making an effort TO have
some of the schools take il up MS n part
of their course Of instruction. Speaking
Of the new method, Mr.. Hinklc said:
us the systei lsound? Isit practical?
Yes, most emphatically to both qucs-
tons. 1t is natural computation. and IL
is just as easy to teach a child or grown
person the relationship Of numbers ms il
is to teach them the relationship BE-
tween persons. Use 100 for the head "
the geological tree Of the family IF fig
ures. and it is 5ust rs easy and natural
to teach . child that 25 per cent of any
amount is one-fourth of il. because %
is one-fourth Of 100. as it is To teach
him that that old gentleman is his
grandfather because he is his mothers
father, or that 12is per cent is one
eighth of any amount, because il is one
| eighth Of 100, as il is to teach him that
the curly head over. there is his cousin
because he is his fathers brothers child.
"I1l give you some examples in shore
mental arithmetic for a change. Say
you buy so yards Of CARPET mt 62i.
cents; 62is cents is fi%ve-cighths Of 100;
five-eighths If so is $50. Easy number,
yes. Take an odd me Say s3 yards nj
621s cents; f~ive-eighths of so is geo: add
three times 62 ! cents. which is 81. ST., /;
total. ss1.s71l. Say you buy 49, yards
of dress goods at s3ls cents; 33i cents
is one-third IF 100; one-third Of Is. is
So. 66e5. Say you sell 35O pounds Of
wool at 1914 cents; 1871 is one-sixth If
100; one-sixth of $50 is t5s. 331z. say
you buy 100 bushels of potatoes at so
cents. $50. Easy, isn'tit? But if il were
90 bushels at 40 cents you couldn't do it
80 easily, and yet it is no harder, il you
only knew it. Say 30 times 80 is $i9. 30,
less nee 90, which il t4S. 81, and it is
no more difficult than 100 times 30.
almost every child can do multiple
cation up to IL, but how many older
people a 20 higher than IL easily?
Yet it is easy to go to 600 if he is a
quick adder. l think my rule for squar-
ing large numbers il simpler than Mr..
Speers' way of doing it. For example.
start at IL. Twelve times la is Ia. To
get the square II IL, add I3 aud IL to
square Of 12; 13 and IL make -: -
tn IA is 169. Square Of 14-l4 md I3
equals %; add to 1863, makes 1876. To
square 15-15 and IL equals 90. added
to 1876 is 225. The square Of 30 is =. 500.
To get square Of 5l-5I and 10 are
lO1. added to 9, 800 equals 2.601. To
square 49-49 and 80 are %; subtract
from 1880 is 2, 4OI. The square Of 100
is 10, 600. To get square of 99-99 and
100 are 1879 subtract from 10, 900. equals
$50. To square 10l-i0I and 100 are
2Ol. add to 10. 900. equals 10, 2OI.
This may look hard to some, but
when one has been drilled in multiply
ing larger numbers mentally il is as
easy as falling OF a house. Some will
complain that I have no right to say
in so yards Of carpet at 62ie cents
fve-eighths of so is ESQ; that I don't
point off according to rules. Well.
that's inst what I don't want tn do
that is where time is lost. With the
drilling which a pupil would get prior
To doing this work. one Of the impor-
tant things taught him would be IN
know that so yards at 62i. cents of
ive-eighths of so. as in this case. would