The difference between 91 and 72 is: 
The difference between 66 and 30 is: 
The difference between 94 and 72 is: 
The difference between 91 and 70 is: 
The difference between 91 and 72 is: 
The difference between 91 and 42 is: 
The difference between 99 and 70 is: 
The difference between 91 and 72 is: 