The difference between 81 and 37 is: 
The difference between 50 and 31 is: 
The difference between 88 and 37 is: 
The difference between 81 and 30 is: 
The difference between 81 and 37 is: 
The difference between 81 and 57 is: 
The difference between 87 and 33 is: 
The difference between 81 and 37 is: 