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.