Evening star. [volume] (Washington, D.C.) 1854-1972, 1908-10-18
By Frederic B. Emery

some one thinks OF, de-
pending upon simple number relations.
Let some one choose any number and null
tiply it by g. If the product is even, divide it
by a. if odd. add 1 and then divide by 2.
Then multiply the result by 8, and divide the
product by g, neglecting any remainder, and
call the quotient n. The number thought of
will be an if the product when the number first
thought of multiplied by 3 even; it will be
an plus if that product was odd; Suppose
3 was the number thought of. Multiply by
3 90; since 9 is odd add (1o); divide by 2
81; multiply by (15); divide by 9. neglect
ing the remainder (1). If is then called n, ~
plus is 3, the number thought of at first. If
4 was the number multiply by 8 C2); divide
by (6); multiply by (1S); divide by (2).
If is 2, is 4, the original number.
Another method is to multiply the number
by S, add 6, multiply by 4, add O. multiply by
s, and subtract los. That result divided by
100 will be the number first thought of. Thus.
start with 8. Multiply by (4o) add 90:
by (o6s); subtract ros (soo): divide by 100.
gives the original number.
This may be varied in several ways. We may
have the person first multiply by S, add 6.
multiply by 2. add s, multiply by 5, subtract
Multiply by (ss); add .(4); multiply by
(S2j; add (oo); multiply by (45o); SUBJ
tract 100 $500; divide by so Cd.
Or he may first multiply by 9, add 10, null
hply by S, subtract IS, multiply by 4, add
and divide by 200. Thus, start with 9. Null
tiply by (SI); add 10 (o1); multiply by S
(4SS); subtract IS G3o); multiply by
G,72o); plus 20 times (I,9oo); subtract 100
(I.8oo); divided by 200 (o).
The operator must stop at such point that
the person who has chosen the number does
not know the last two or three operations. In
that way and by varying the stopping point it
IS usually puzzling to decipher the method at
first.
of come ono choose come number saw ~
Have him multiply it by any number you
choose, say a; then add to that result any
value you choose, say b; then divide by any
number you choose, say C.; then find a OF the
the result obtained when the division by was
made. The result will always be value equal
to c, and since you know the values of and
it is easy for you to tell the answer Thus,
suppose you decide that you will use the
values equals 4. b equals s, and equals g.
Let the person choose any number, say q. He
then multiphes by a, A. getting "a; then
adds b, or (2o); then divides by c, or q S o.;
G. 4 6, of the original number, g, is 4, and
when he subtracts from SO the result is
s g, which is BIC.
How to Tell Three Numbers
HERE is method of telling three numbers
at once. Let the person choose any three
Of them by g. add 3, multiply by s. and add 7.
Then add the second number, multiply by 2,
and add 3. Then add the third number.
If he tells you the result at this point,
you simply subtract 235 from his result, and
the difference will g We you the three numbers.
Thus, suppose he chooses ISL. Call the first
number !; multiply by 90; add Oh;
multiply by 5 $50; add ! (o2); add the second
number (Ioo); multiply by (2oo); add 3
(2os); multiply by (I,o15); add the third
number, (I,oI6). You subtract 2,s, and the
result is 7S1, or the three numbers thought of.
The results will come out Just as we'll no matter
which of the three numbers is taken for the