The difference between 17 and 13 is: 
The difference between 33 and 14 is: 
The difference between 18 and 13 is: 
The difference between 17 and 13 is: 
The difference between 87 and 13 is: 
The difference between 17 and 13 is: 
The difference between 20 and 16 is: 
The difference between 17 and 13 is: 