The difference between 21 and 19 is: 
The difference between 93 and 56 is: 
The difference between 29 and 19 is: 
The difference between 21 and 10 is: 
The difference between 21 and 19 is: 
The difference between 21 and 19 is: 
The difference between 28 and 16 is: 
The difference between 21 and 19 is: 