The difference between 91 and 60 is: 
The difference between 50 and 45 is: 
The difference between 93 and 60 is: 
The difference between 91 and 60 is: 
The difference between 81 and 60 is: 
The difference between 91 and 20 is: 
The difference between 100 and 69 is: 
The difference between 91 and 60 is: 