The difference between 51 and 30 is: 
The difference between 91 and 87 is: 
The difference between 58 and 30 is: 
The difference between 51 and 30 is: 
The difference between 61 and 30 is: 
The difference between 51 and 10 is: 
The difference between 60 and 39 is: 
The difference between 51 and 30 is: 