The difference between 80 and 10 is: 
The difference between 74 and 73 is: 
The difference between 87 and 10 is: 
The difference between 80 and 10 is: 
The difference between 20 and 10 is: 
The difference between 80 and 40 is: 
The difference between 81 and 13 is: 
The difference between 80 and 10 is: 