The difference between 77 and 39 is: 
The difference between 65 and 41 is: 
The difference between 79 and 39 is: 
The difference between 77 and 33 is: 
The difference between 47 and 39 is: 
The difference between 77 and 19 is: 
The difference between 78 and 30 is: 
The difference between 77 and 39 is: 