Calculator Tricks 3
By
Brian Carruthers
(Please see notes on slide 1)
The answer will always be
37
Think of a four-digit
number and enter it
twice into your
calculator.
 For example: 12341234

I think that the number
you have chosen
is divisible by 137
Don’t you believe me?
Why don’t you check
this on your calculator?
Now divide your
eight-digit number
by your original
four-digit number
Guess what?
The answer is
73
How did I know?
Watch This:
Entering a four-digit
number twice (12341234) is
the same as multiplying it
by 10001.
 (1234 x 10001 = 12341234).

Because 10001 = 73 x 137:

the eight-digit number will
be divisible by 73, 137, and
your original four-digit
number.
What did you think of
that?
Isn’t Maths amazing?