The difference between 81 and 18 is: 
The difference between 56 and 48 is: 
The difference between 89 and 18 is: 
The difference between 81 and 10 is: 
The difference between 31 and 18 is: 
The difference between 81 and 38 is: 
The difference between 84 and 11 is: 
The difference between 81 and 18 is: 