I saw an effect recently at my college when a magician. He did a variety of effects; Chop Cup, card routines, Coin Matrix; but I asked if he knew any Mentalism and he showed me something which I find both impressive and confusing.
He took out a small bit of card, and an equally small brown envelope. Said he was going to guess how much change I had on me; and then appeared to write something something down on the back of the card.
Now at this stage, I was fully expecting a swami -but there was people around so I played along- and he sealed up the envelope and handed it to me.
We counted my money (£28.70) and he had it exactly right... but he never touched the envelope. That's what confuses me, I even offered it back to him for him to open... and he refused it; instead asking me to open it and read the card.
Does anyone know where such a trick can be learnt? Because that's a very good one

Tom
xx