Evening journal., 1896-11-02
A SWIFT All FIGURES.
EDUCATIONAL CIRCLES EXCITED OVER
LIGHTNING ARITHMETIC.

lie Giyes Newspaper Man Some Illus
trations Of His Method.
Educational circles arc in 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 20 use to advan-
/ tage any sort of rapid calculation. The
/ incident and the attending interest led
a repr sentative to make some inquiry
into neither or not there is any move
ment to introduce the new system in
the schools Of this city. Although it is
the subject Of not a little discussion
among the teachers Of the city, 10 steps
have rs yet been taken.
One Of the most interested in this city
is Mr. O. d. Hinkle, who is connected
with the Nj. G. Lilley company Mr..
Hinkle has been in the mercantile bust
ness Tor number Of years, much Of
which timo has been spent in this city,
and his been regarded as one of the
] UlNnN 1AlJAl AtARA-aAalo III AAAt nActls Ills
work mas not been on the fancy order
but ST iraightforward use Of rapid meth
ods il practical business. Having seen
MI Einkle add subtract, divide and
multi by long lists Of figures in billing
out goods Of all sorts as fast as his as
sistan. could call them off to him, and
{ in SOC pages Of ledger accounts having
made not one single mistake, Tho Dis
] patch was interested 70 know whether
the system mentioned in Chicago was
3, related in any way to that which he
used
Mr. Hinklo was found most onthusi-
I asticaily interested in tho method. and
: quickly remarked, upon being asked
that tle supposed new system was iden-
I ticallv the Same that he has been using
+. for 2j 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 it up as a part
Of their course Of instruction. Speaking
Of the now method, Mr.. Hinkle said
'Is the system sound? Isit practical?
+, Yes. most omphatically TO both qucs-
I. tions. Ii is natural computation, and IL
. is JUS as easy to teach child or grown
{ person the relationship of numbers as it
is to teach them tho relationship be-
/. tween persons. Uso 100 for the head of
the geological tree Of the family Of fig
ures, and it ia just rs easy and natural
i. to teach n child that 20 per cent of any
: amount is ono-fourth of it, because 20
is one.fourth Of 100, as it is to teach
d him that that old gentleman is his
II grandfather because no is his mother
= father, or that 1919 per cent is ono.
n eighth of any amount because it is one
e eighth Of 100, as it is TO teach him that
the curly head over there is his cousi1
$ because he is his father s brothers child
'I'u give you some examples in shor
mental arithmetic for change. Sa.
yoa huy 80 yards Of carpet at G21
70 cents: 69 y cents is five-eighths of 100
ve-eighths Of 80 is $50. Easy number
H. yes Take an odd one. Say SO yards q
62S cents; fve-oighths of so is $50; adj
Y. three times G2 - cents, which is 81. S718
n total, S61.671s. Say you buy l67 yard
e. of dress goods at 33 y cents; 1919 cent
y is one-third Of 100; one-third of 167
tn 500. GG2l. Say you sell $50 pounds c
wool at lGH cents; l61l is ono-sixth {
2g 100; one-sixth Of $50 is $58.331s. Sa
rs you buy 100 bushels Of potatoes at 8
cents. 500. Easy. isn'tit? But if itwel
a. 80 bushels at 40 cents you couldn't do
u so easily, and yet it is 10 harder, If yo
only lnew it. Say 90 times 50is sac. 81
"a, less once 90, which is S4s.5l, and it
no moro difficult than 100 times 90
Almost every child can do multipl
cation up 10 -, but how many old'
l. people can go higher than ~ oasil,
L Yet it is casy t2 60 TO 600 If ho ~
quick adder. / ehinls my rule for sqra
ny ing large numbers i5 gi-.pler than n
we Speers' way of doing it. For oXampl
lay start at -. Twclvc times l2 is ia. 2
on, pet ito sqrarc cf l3, Gdd13 and ! >
loi square Of 10; 13 nmd 3 mako 20
,,-o to I4s is 1G0 Square Of l4-l4 and
om equal 81; add to 100, makes l96
+ 9 squarf l5--l5 and IA equals 20, add'
to 100 is 225. Tho square Of so is ., so
70 gct square Of 51--51 and 90 a
iO1. addcd to ., 500 equals 2,6Ol.
ew square 4g-A0 and 90 are 90; subtra
est from 9, 500 il 2,4Ol. The square Of II
eS 95o is 10, 600. TO get square Of 900 "a
80 100 are 100 subtract from 10, OOO,e ,equa
atc 9,S10. To square 1Ol-10l and 100 a
Dok 2Ol, add to 10, OC0, equals l0,20l.
"This may look hard to some, b
when ono has been drilled in multipl
ing larger numbers mentally it is
nm easy Us falling Off q house. Some W
cm complain that have no right to s
q in so yards Of carpet at 62ls ceI
10 flve-eighths Of so is 500; that dol
mn point off according TO rules. We
o' that's just what 1 don't want to dc
that is where time is lost. With
drilling which pupil would get pr
un to doing this work, one Of the imp
on tant things taught him would be
nit know that so yards at G2la cents
ugh fvo-eighths Of 80. as in this case, woI
.'el be $50. and not So or $500 or So, o.
l''' which often occurs with pupils who
the old rules for pointing off. One
mechanical ard liable to disastr'
lin, blunders tho other has become intuit