The difference between 87 and 23 is: 
The difference between 99 and 42 is: 
The difference between 85 and 23 is: 
The difference between 87 and 21 is: 
The difference between 47 and 23 is: 
The difference between 87 and 63 is: 
The difference between 91 and 27 is: 
The difference between 87 and 23 is: 