The difference between 81 and 72 is: 
The difference between 70 and 23 is: 
The difference between 85 and 72 is: 
The difference between 81 and 70 is: 
The difference between 91 and 72 is: 
The difference between 81 and 22 is: 
The difference between 89 and 70 is: 
The difference between 81 and 72 is: 