Mary is baking a cake. The recipe calls for 6 cups of sugar and 9 cups of flour. She already put in 2 cups of flour. How many more cups of flour than cups of sugar does she need to add now?
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First, we need to figure out how many cups of sugar she has left to add. We know that she started with 6 cups of sugar, and she's already added 2 cups of sugar. So she has 6 - 2 = 4 cups of sugar left to add. 

Next, we need to figure out how many cups of flour she has left to add. We know that she started with 9 cups of flour, and she's already added 2 cups of flour. So she has 9 - 2 = 7 cups of flour left to add. 

Finally, we need to figure out how many more cups of flour than cups of sugar she needs to add. We know that she needs to add 4 cups of sugar and 7 cups of flour. So she needs to add 7 - 4 = 3 more cups of flour than cups of sugar.