The difference between 15 and 13 is: 
The difference between 74 and 25 is: 
The difference between 16 and 13 is: 
The difference between 15 and 11 is: 
The difference between 65 and 13 is: 
The difference between 15 and 13 is: 
The difference between 21 and 19 is: 
The difference between 15 and 13 is: 