instruction:
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.
question:
Greg and Sharon own neighboring cornfields . Greg harvested 0.4 acre of corn on Monday and Sharon harvested 0.1 acre . How many more acres did Greg harvest than Sharon ?
answer:
0.3


question:
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 ?
answer:
72


question:
Gwen bought two coloring books . One had 10 pictures and the other had 39 . After one week she had already colored 13 of the pictures . How many pictures does she still have to color ?
answer:

36