Take a 50, 100 ou 200-Franc bill (or a lottery ticket with 9 digits). Hide the serial number (9 digits) so that I can't see it. Now calculate : Give me the sum of the first and the second digits. Then the sum of the third and the fourth digits... and so on until you get to the ninth and last digit. Finally give me the sum of the first and the last digits again.
first plus second, second plus third, third plus fourth, fourth plus fifth, fifth plus sixth, sixth plus seventh, seventh plus eighth, eighth plus ninth, first plus ninth .

Got it ! Here is the serial number of your bill :

Royal V.Heath's bill trick.(*1)   

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

  (*1) Paris' fashion. These cards come from a game showing fashion plates.
It was published in Paris circa 1850 by the fashion newspaper "Le Caméléon" .
The original can be found at La Bibliothèque Nationale, Paris.