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.

[EX Q]: Lucy went to the grocery store . She bought 12 packs of cookies and 16 packs of noodles . How many packs of groceries did she buy in all ?
[EX A]: 28

[EX Q]: A pet store has 9 bird cages . If each cage has 2 parrots and 6 parakeets in it , how many birds does the pet store have total ?
[EX A]: 72

[EX Q]: A physician 's assistant measures a child and finds that his h8 is 41.5 inches . At his last visit to the doctor 's office , the child was 38.5 inches tall . How much did the child grow , in inches ?
[EX A]:
3