The difference between 40 and 15 is: 
The difference between 87 and 51 is: 
The difference between 46 and 15 is: 
The difference between 40 and 10 is: 
The difference between 20 and 15 is: 
The difference between 40 and 25 is: 
The difference between 49 and 14 is: 
The difference between 40 and 15 is: 