You are given a math word problem and you are supposed to only use subtraction on the numbers embedded in the text to answer the following question and then only report the final numerical answer.

[EX Q]: Context: Jerry had some action figures on a shelf in his room. Later he added 2 more action figures to the shelf and removed 7 of the old ones. If there are 10 action figures on his shelf now 

 Question: How many action figures did he have initially on the shelf?
[EX A]: 15

[EX Q]: Context: Mary is baking a cake. The recipe calls for 3 cups of sugar and 10 cups of flour. She already put in some cups of flour. If she still needs 5 more cups of flour than sugar 

 Question: How many cups of flour did she put in?
[EX A]: 2

[EX Q]: Context: Ed had 30 more marbles than Doug. Ed lost 21 of his marbles at the playground. If Ed had 91 marbles 

 Question: How many more marbles did Ed have than Doug then?
[EX A]:
9