The difference between 51 and 20 is: 
The difference between 53 and 10 is: 
The difference between 55 and 20 is: 
The difference between 51 and 20 is: 
The difference between 51 and 20 is: 
The difference between 51 and 10 is: 
The difference between 60 and 29 is: 
The difference between 51 and 20 is: 