26 Nov 2006
Have you sussed out how it works ?
Lets suppose you choose your 2 digit number as 'ab'.
Its numeric value = 10a + b
Now add the digits = a + b
Now subtract them = 10a + b - (a + b)
= 10a + b - a - b
= 9a
So the answer is always a multiple of 9: 9, 18, 27, 36, etc. You'll notice that multiples of 9 always have the same symbol on the final symbol map.
The clever thing is that they switch the symbols around each try.
Sorry to be so late: I've only just joined.