The difference between 90 and 81 is: 
The difference between 98 and 73 is: 
The difference between 99 and 81 is: 
The difference between 90 and 80 is: 
The difference between 90 and 81 is: 
The difference between 90 and 71 is: 
The difference between 99 and 80 is: 
The difference between 90 and 81 is: 