What Number Please? by Harvey Raft - Trick

Effect: A volunteer chooses a telephone number from 1 of 4 cards and writes it on a piece of paper. The performer then asks the volunteer if its color is Red or Black. This process is repeated with ll 4 cards. To assist the volunteer in finding his/her number the first 3 digits of the telephone numbers are in numerical order on the cards. The performer reveals the volunteer's chosen telephone number.