Spell by Numbers by Adam Hudson

After a spectator freely selects a three digit number and enters it into their mobile phone's calculator, they perform one simple calculation to get a decimal and the first six numbers are converted into letters. Each letter is then written on a large pad or blackboard for all to see. The entire audience now plays along, mentally working to unscramble the jumble of letters into an actual word within 30 seconds. When someone raises their hand and gives you the answer, you redirect everyone's attention to a person who has been holding a card with your prediction since the beginning of the effect. He or she now turns it over to reveal a picture of the random word just formed! No math or memory work whatsoever, the effect is fun and easy to perform