Every day Ryan spends 4 hours on learning english, 21 hours on learning chinese and 7 hours on learning spanish. How many more hours does he spend on learning chinese than he does on learning spanish?
How many hours does he spend on learning english? 
4 hours 

How many hours does he spend on learning chinese? 
21 hours 

How many hours does he spend on learning spanish? 
7 hours 

To find out how many more hours he spends on learning chinese, we need to subtract the number of hours he spends on learning spanish from the number of hours he spends on learning chinese. 

21 hours - 7 hours = 14 hours 

So, Ryan spends 14 more hours on learning chinese than he does on learning spanish.