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]: Arthur baked 35 muffins . How many more muffins does Arthur have to bake to have 83 muffins ?
[A]: 48

[Q]: Joan has 47 green and 48 red marbles . Fred took 24 of Joan 's green marbles . How many green marbles does Joan now have ?
[A]: 23

[Q]: A restaurant served 7 slices of pie during lunch and 5 during dinner today . It served 8 of them yesterday . How many slices of pie were served today ?
[A]:
12