The difference between 68 and 16 is: 
The difference between 91 and 40 is: 
The difference between 68 and 16 is: 
The difference between 68 and 13 is: 
The difference between 98 and 16 is: 
The difference between 68 and 56 is: 
The difference between 71 and 19 is: 
The difference between 68 and 16 is: 