The difference between 91 and 12 is: 
The difference between 99 and 66 is: 
The difference between 99 and 12 is: 
The difference between 91 and 10 is: 
The difference between 71 and 12 is: 
The difference between 91 and 52 is: 
The difference between 99 and 10 is: 
The difference between 91 and 12 is: 