The difference between 37 and 31 is: 
The difference between 52 and 25 is: 
The difference between 34 and 31 is: 
The difference between 37 and 30 is: 
The difference between 77 and 31 is: 
The difference between 37 and 21 is: 
The difference between 40 and 34 is: 
The difference between 37 and 31 is: 