The difference between 40 and 40 is: 
The difference between 91 and 63 is: 
The difference between 48 and 40 is: 
The difference between 40 and 40 is: 
The difference between 60 and 40 is: 
The difference between 40 and 10 is: 
The difference between 40 and 48 is: 
The difference between 40 and 40 is: 