Choose
any number, for example 7146.
Cross one of the digits out (except
for 0), 4 for example.
Then you get a number with one digit
less.
Subtract the sum of the digits of the number you first chose
( 7+1+4+6 = 18).
Give me your result (you got 698).
So
I'm going to find out the number you hid !
Result
of your difference :



You
crossed out number : 


