it may be worth recalling that in maths, our teacher made us do similar tricks, and it went like: choose a number, n add 2, n+2 multiply it by 2, 2n+4 take away 4, 2n and divide by your original number, 2 it would always give the answer of two i think this uses a similar trick FINALLY! GCSE MATHS WAS ACTUALLY USEFUL (psych)