The difference between 67 and 31 is: 
The difference between 42 and 33 is: 
The difference between 67 and 31 is: 
The difference between 67 and 30 is: 
The difference between 87 and 31 is: 
The difference between 67 and 51 is: 
The difference between 73 and 37 is: 
The difference between 67 and 31 is: 