The difference between 91 and 44 is: 
The difference between 48 and 13 is: 
The difference between 99 and 44 is: 
The difference between 91 and 40 is: 
The difference between 81 and 44 is: 
The difference between 91 and 54 is: 
The difference between 99 and 42 is: 
The difference between 91 and 44 is: 