The difference between 90 and 15 is: 
The difference between 87 and 28 is: 
The difference between 97 and 15 is: 
The difference between 90 and 10 is: 
The difference between 60 and 15 is: 
The difference between 90 and 25 is: 
The difference between 99 and 14 is: 
The difference between 90 and 15 is: 