, halve it (10), and multiply it by 4 (40). Then ask him how
many that makes. He will say 40. You divide this in your mind by 2
(20), subtract 6 (14), divide by 2 again (7), and astonish him by
saying that the number of which he thought was 7.

To Guess Any Even Number Thought of

In this case you insist on the number chosen being an even number. Let
us suppose it is 8. Tell him to multiply by 3 (24), halve it (12),
multiply by 3 again (36), and then to tell you how many times 9 will
go into the result. He will say 4. Double this in your mind and tell
him that he thought of 8.

To Guess the Result of a Sum

Another trick. Tell the person to think of a number, to double it, add
6 to it, halve it and take away the number first thought of. When this
has been done you tell him that 3 remains. If these directions are
followed 3 must always remain. Let us take 7 and 1 as examples. Thus 7
doubled is 14; add 6 and it is 20; halved, it is 10; and if the number
first thought of--7--is subtracted, 3 remains. Again, 1 doubled is 2;
6 added makes 8; 8 halved is 4, and 1 from 4 leaves 3.

A more bewildering puzzle is this. Tell as many persons as like to, to
think of some number less than 1,000, in which the last figure is
smaller than the first. Thus 998 might be thought of, but not 999, and
not 347. The amount being chosen and written down, you tell each
person to reverse the digits; so that the units come under the
hundreds, the tens under the tens, and the hundreds under the units.
Then tell them to subtract, to reverse again, and add; remarking to
each one that you know what the answer will be. It will always be
1089. Let us suppose that three players choose numbers, one being 998,
one 500, and one 321. Each sets them on paper, reverses the figures,
and subtracts. Thus:--

998 500 321
899 005 123
--- --- ---
099 495 198

The figures are then reversed and added. Thus:--

099 495 198
990 594 891
---- ---- ----
1089 1089 1089

Guessing Competitions

Guessing competitions, which are of American invention, can be an
interesting change from ordinary games. In some the company are all
asked to contribute, as in "Book Teas," where a punning symbolic title
of a book is worn by each guest, and a prize is given to the person
who guesses most, and to the person whose title is considered the
best. Thus, a person wearing a card having the letter R represented
_Middlemarch_, and a p