The difference between 66 and 51 is: 
The difference between 67 and 16 is: 
The difference between 68 and 51 is: 
The difference between 66 and 50 is: 
The difference between 96 and 51 is: 
The difference between 66 and 21 is: 
The difference between 72 and 57 is: 
The difference between 66 and 51 is: 