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

Q: Tom went to 4 hockey games this year , but missed 7 . He went to 9 games last year . How many hockey games did Tom go to in all ?

A: 13
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Q: Donna weighs 69 pounds . Willie weighs 51 pounds . How much heavier is Donna than Willie ?

A: 18
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Q: Nancy was organizing her book case making sure each of the shelves had exactly 6 books on it . If she had 2 shelves of mystery books and 6 shelves of picture books , how many books did she have total ?

A:
48
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