The difference between 52 and 20 is: 
The difference between 71 and 68 is: 
The difference between 56 and 20 is: 
The difference between 52 and 20 is: 
The difference between 72 and 20 is: 
The difference between 52 and 10 is: 
The difference between 60 and 28 is: 
The difference between 52 and 20 is: 