The difference between 40 and 21 is: 
The difference between 84 and 69 is: 
The difference between 49 and 21 is: 
The difference between 40 and 20 is: 
The difference between 30 and 21 is: 
The difference between 40 and 21 is: 
The difference between 49 and 20 is: 
The difference between 40 and 21 is: 