Mary is baking a cake. The recipe calls for 9 cups of flour and 11 cups of sugar. She already put in 4 cups of flour. How many more cups of sugar than cups of flour does she need to add now?
First, we need to find how many cups of flour are left. 9 cups of flour minus 4 cups of flour is the same as 9 - 4 cups of flour, which is 5 cups of flour. 

Next, we need to find how many cups of sugar are left. 11 cups of sugar minus 4 cups of flour is the same as 11 - 4 cups of sugar, which is 7 cups of sugar. 

Now, we need to find the difference between the cups of sugar and the cups of flour. The cups of sugar is 7 and the cups of flour is 5, so the difference is 2. 

Therefore, Mary needs to add 2 more cups of sugar than cups of flour. 

Therefore the answer (numeric) is: 

2