The difference between 30 and 18 is: 
The difference between 39 and 24 is: 
The difference between 39 and 18 is: 
The difference between 30 and 10 is: 
The difference between 60 and 18 is: 
The difference between 30 and 28 is: 
The difference between 33 and 11 is: 
The difference between 30 and 18 is: 