Lucy went to the grocery store. She bought 10 packs of cookie and 4 packs of cake. How many more packs of cookie did she buy over cake?
Let's denote the number of packs of cookies by c and the number of packs of cake by k. 

Then we have the equation: 

c+k=14. 

The difference between the number of packs of cookies and the number of packs of cake is 

c-k=6. 

Therefore the answer (numeric) is: 

6