The difference between 77 and 18 is: 
The difference between 81 and 67 is: 
The difference between 79 and 18 is: 
The difference between 77 and 12 is: 
The difference between 37 and 18 is: 
The difference between 77 and 58 is: 
The difference between 79 and 10 is: 
The difference between 77 and 18 is: 