^ lol, nah.. 47 is a particular tooth.
Dentists and the oral profession refer to a certain tooth with a double digit number. They divide s/o's teeth in 4 quarters.. left jaw (under thus) is 1 and for instance the pointy (carnivorous) front tooth there is 13. Well, they start counting from the middle of one's front (ripper) teeth. 11 and 12 are the ripper teeth in one's left jaw.
Right teeth-row under is 4 and counting from the middle it was the seventh tooth (the lousy buggering molar) there. 47 thus.
Um, hope that's an understandable explanation.