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.
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Question: Before December , customers buy 1346 ear muffs from the mall . During December , they buy 6444 , and there are none . In all , how many ear muffs do the customers buy ?

Answer: 7790


Question: A group of 3 friends went into a restaurant . The chef already had 6 chicken wings cooked but cooked 3 more for the group . If they each got the same amount how many would each person get ?

Answer: 3


Question: When Jake had 1 cat , he needed to serve 0.5 can of cat food each day . Now that Jake has adopted a second cat , he needs to serve a total of 0.9 can each day . How much extra food is needed to feed the second cat ?

Answer:
0.4