The difference between 40 and 16 is: 
The difference between 81 and 35 is: 
The difference between 49 and 16 is: 
The difference between 40 and 10 is: 
The difference between 90 and 16 is: 
The difference between 40 and 36 is: 
The difference between 49 and 15 is: 
The difference between 40 and 16 is: 