The difference between 81 and 67 is: 
The difference between 75 and 71 is: 
The difference between 89 and 67 is: 
The difference between 81 and 60 is: 
The difference between 91 and 67 is: 
The difference between 81 and 37 is: 
The difference between 85 and 61 is: 
The difference between 81 and 67 is: 