The difference between 31 and 15 is: 
The difference between 85 and 13 is: 
The difference between 37 and 15 is: 
The difference between 31 and 10 is: 
The difference between 41 and 15 is: 
The difference between 31 and 25 is: 
The difference between 36 and 10 is: 
The difference between 31 and 15 is: 