, 1896-10-12
A SWIFT AT FIGURES.

A SN AT FIGURES.
EDUCATIONAL CIRCLES EXCITED OVER
LIGHTNING ARITHMETIC.
An Ohio Man Has = System Which He
Thinks Should He Taught In the Schools
He Gives . Newspaper Man Some Illus
srations 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 can be able to use to advan-
tage any sort Of rapid calculation. The
incident and the attending interest led
q representative to make some inquiry
into whether or not there is any nov
ment to introduce the new system i'll
tho schools of this city. Although it is
the subject Of not a little discussion
among the teachers of the city, nc steps
have as yet been taken.
One of the most interested in this city
is MIR. o. D. Hinkle, who is connected
with the NJ. G. Lilley company. Mr..
Hiukle has been in the mercantile bust
ness for a number of years, much Of
which time has been spent in this city,
and has been regarded as one Of the
most rapid calcula:ora in the state. His
work has not been on tie 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 as his as
sistant could call them off to'him, and
in 500 pages Of ledger accounts having
made not one single mistake, Tho lis
patch was interested to know whether
the system mentioned in Chicago was
related in any way to that which he
used.
Mr.. Hinkle was found most enthusi-
astically interested in the method, and
quickly remarked, upon being asked,
that the supposed new system was iden.
tically the same that he has been using
for 20 years. Indeed, Ar. Hinkle has
been for a number Of years thinking &C.
riously Of making Ill effort to have
some Of tire schools take it mp rs n part
of their course Of instruction. Speaking
Of the new method. MIR. Hinkle said:
lis the system sound? Is it practical?
Yes, most emphatically to both ques-
lions. It is natural computation, and it
is just as easy to teach a child or grown
person the relationship Of numbers us it
is to teach them the relationship be-
tween persons. Use 100 for the head Of
the geological tree of the family Of fig
ures, and it is just ms easy and natural
to teach a child that rs per cent Of any
amount is one-fourth of it, because 20
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 1917 per cent is one-
eighth Of any amount, because it is one
eighth of 100, u it is to teach him that
the curly head over there is his cousin
because he is his father brothers child.
"I'll give you some examples in short
mental arithmetic for a change. Say
You buy 80 yards Of carpet at 621a
cents; 62ls cents is five-cighths Of 100;
five-eighths of 80 is 500. Easy number,
yes. Take an odd one. Say SO yards ut
8215 cents; five-eighths Of so is 500; add
three times So Il cents, which is 81. s7k (;
total, s61.s71a. Say you buy 1877 yards
Of dress goods ut 8315 cents; 83h cents
is one-third Of 100; one-third Of 1877 is
$55. 662s. Say you sell $50 pounds Of
wool at 1871 cents; 1914 is one-sixth Of
100; one-sixth Of $50 is *5S. 33h. Say
you buy 100 bushels Of potatoes at so
cents, $50. Easy, isn'tit? But if it were
80 bushels at 40 cents you couldn't do it
10 easily, and yet it is no harder, if you
only knew it. Say 90 times so is $40. so,
less once 90, which is s4S. 81, and it is
no more difficult than 100 times 90.
almost every child can do multiple
cation up to IL, but how many older
people can 20 higher than IL easily3
Yet it is easy to go to 500 if he is q
quick adder. I think my rule for squar.
ing large numbers is simpler thar Mr..
Speers' way Of doing it. For example,
start at IL. Twelve times IL is la. To
get the square Of IS, add Is and IL to
square Of l2; IS and - make rs; 25
to 144 is 1859. Square Of 14-14 and IS
equals 81; add to 100, makes 1876. To
square 1916 and IA equals 80, added
to 1875 is 225. The square of so is 2, 500.
To get square Of 51-51 and 80 are
101, added to $500 equals 2,601. To
square 1910 and 80 are 90; subtract
from 9, 500 is ., 4O1. The square Of 100
Is 10, 900. To get square of 900 ind
100 are 1879 subtract from 10000. equals
$50. To square l01-l01 and 100 are
20l. add to 10, 900, equals 10. 201.
"This may look hard to some, but
when one has been drilled in multiply
ing larger numbers mentally it lie as
easy as falling of a house. Some will
complain that I have no right to say
in 80 yards If carpet at 62H cents
nve-eighths Of 80 is $50; that I don't
point of according to rules. Well.
that's just what I don't want to do
that IL where time is lost. With the
drilling which a pupil would get prior
to doing this work, n Of the impor-
tant things taught him would be to
know that so yards at 62H cents Of
ave-eighths Of 80. a. in this case, would
be $50, and not e5 or $500 or %, 900.
which often occurs with pupils who use
tho old rules for pointing on. One is
mechanical and liable to disastrous
blunders; the other has become intuitive
IRON good drilling and il = sure thing
alwayA There are legions Of doubling
Thomases, the most Of whom will not
look into this closely enough to under
akand Il. who will advnnce ali kind AZ