The difference between 90 and 28 is: 
The difference between 66 and 36 is: 
The difference between 99 and 28 is: 
The difference between 90 and 20 is: 
The difference between 70 and 28 is: 
The difference between 90 and 18 is: 
The difference between 99 and 27 is: 
The difference between 90 and 28 is: 