The difference between 77 and 40 is: 
The difference between 85 and 21 is: 
The difference between 79 and 40 is: 
The difference between 77 and 40 is: 
The difference between 77 and 40 is: 
The difference between 77 and 40 is: 
The difference between 81 and 44 is: 
The difference between 77 and 40 is: 