The difference between 71 and 15 is: 
The difference between 89 and 21 is: 
The difference between 79 and 15 is: 
The difference between 71 and 10 is: 
The difference between 61 and 15 is: 
The difference between 71 and 25 is: 
The difference between 77 and 11 is: 
The difference between 71 and 15 is: 