The difference between 72 and 31 is: 
The difference between 70 and 15 is: 
The difference between 75 and 31 is: 
The difference between 72 and 30 is: 
The difference between 72 and 31 is: 
The difference between 72 and 51 is: 
The difference between 80 and 39 is: 
The difference between 72 and 31 is: 