The difference between 13 and 11 is: 
The difference between 93 and 12 is: 
The difference between 17 and 11 is: 
The difference between 13 and 11 is: 
The difference between 73 and 11 is: 
The difference between 13 and 11 is: 
The difference between 21 and 19 is: 
The difference between 13 and 11 is: 