The difference between 51 and 35 is: 
The difference between 69 and 20 is: 
The difference between 57 and 35 is: 
The difference between 51 and 30 is: 
The difference between 91 and 35 is: 
The difference between 51 and 15 is: 
The difference between 57 and 31 is: 
The difference between 51 and 35 is: 