The difference between 81 and 39 is: 
The difference between 22 and 18 is: 
The difference between 89 and 39 is: 
The difference between 81 and 30 is: 
The difference between 91 and 39 is: 
The difference between 81 and 49 is: 
The difference between 83 and 31 is: 
The difference between 81 and 39 is: 