The difference between 90 and 19 is: 
The difference between 54 and 51 is: 
The difference between 99 and 19 is: 
The difference between 90 and 10 is: 
The difference between 90 and 19 is: 
The difference between 90 and 79 is: 
The difference between 94 and 13 is: 
The difference between 90 and 19 is: 